NBS: Nondestructive Evaluation of

Nonuniformities in 2219 Aluminum

Alloy Plate - Relationship to Processing

L Swartzendruber, W. Boettinger, L Ives, S. Coriell, D. Ballard, D. Laughlin, R. Clough, F. Biancaniello, P. Blau, J. Cahn and

R. Mehrabian, Metallurgy Division

G. Free, Electrical Measurements and Standards Division

H. Berger and L. Mordfin, Office of Nondestructive Evaluation

Netfonal Measurement Laboratory

National Bureau of Standards

U.S. Depanrrient o* Commerce

Washington, DC 20234

Phone; (301) 921-2811

1

December 198C

Technical Report

For the Period August 1 97S - September 1 980

NASA Government Order W- 14,637

/ ^ \

j

-QC100

.U56

80-2069

1980

0*

DEPARTMENT OF COMMERCE

ONAL bureau 0? STANDARDS

NBSIR 80-2069

NBS: NONDESTRUCTIVE EVALUATION OF

NONUNIFORMITIES IN 2219 ALUMINUM

ALLOY PLATE - RELATIONSHIP TO PROCESSING

ATIOMAL bureau

OF 8TANDARU8

UB*ART

APR 3 0 1981

f\i a

L Swartzendruber, W. Boettinger, L Ives. S. Corieil. D. Ballard,

D. Laughlin, R. Clough, F. Biancaniello, P. Blau, J. Cahn and

R. Mehrabian, Metallurgy Division

G. Free, Electrical Measurements and Standards Division

H. Berger and L Mordfin. Office of Nondestructive Evaluation

National Measurement Laboratory

National Bureau of Standards

U.S. Department of Commerce

Washington, DC 20234

Phone: (301) 921-2811

December 1980

Technical Report

For the Period August 1 979 - September 1 980

NASA Government Order W- 14,637

U.S. DEPARTMENT OF COMMERCE. Philip M. Klutznick. Secretary

Jordan J. Baruch, Assistant Secretary for Productivity. Tedmology. and Innovatiorr

NATIONAL BUREAU OF STANDARDS, Ernest Ambier, Director
1 /H « * II1I1
i

Nondestructive Evaluation of Nonun1fonn1t1as in 22T9 ...

Aluminum Alloy Plate - Relationship to Processing

ABSTRACT

The compositional homogeneity, microstructure, hardness, electrical

conductivity and mechanical properties of 2219 aluminum alloy plates are

influenced by the process variables during casting, rolling and thermomechanical treatment. Tne details of these relationships have been

investigated for correctly processed 2219 plate as well as for deviations

caused by improper ‘quencning after solution heat treatment. Primary

emphasis has been placeo on the reliability of eddy current electrical

conductivity and hardness as NCE tools to detect variations fn mechanical

prooerties.

Experimental studies were carried out on an industrial size semi -continuous

cast ingot and on various smaller laboratory cast Ingots. The major phases

present in as-cast 2219 aluminum alloy are a-aluminum solid solution, a-CuAl^

and Cu2.-sAly. The positive and negative macrosegregation of alloying elements

was investigated. This macrosegregation is predictable and is caused by

interdendri tic fluid flow during casting. It cannot be completely eliminated

from the finished alloy plate by thermomechanical treatment or scalping and

leads to moderate variations in composition across the plate thickness.

I

I
Experiments conducted on correctly heat treated samples from the laboratory

ingot indicate that mechanical properties are maintained as long as the copper

content is above the maximum solid solubility limit ('^>5.5% Cu). Such was the

case for a commercial alloy plate examineo in this report. Hence the observed pro

perty variation across this as-received plate was not due to composition variation

A comprehensive series of thermomechanical heat treatments on 2219-T87*

aluminum alloy was performed. The hardness and electrical conductivity were

monitored at each stage of the treatment and the mechanical properties of the

finished material were determined. The results were utilized to determine

curves (C curves) that can be used to assess the effect of various quenching

treatments on the final mechanical and NDE properties of the processed

material. These C curves were also used to develop correlations between

the mechanical and electrical conductivity. Such a correlation was

found to exist for alloys (of a single lot) and for improper quenching

from solution heat treatment. Wider excursions from the correct heat

treatment cycle can destroy this correlation.

The precipitation behavior of the 2219 aluminum alloy was examined.

The principal age-hardening phase in properly processed material is 9 '.

The 0" phase is also present and contributes to strength. A pre-aging

heat treatment, or other temperature excursion, .following solution heat

treatment that results in dwell times which are significant in relation to

the C curves, results in the nucleation and rapid growth of 0 and/or o'

precipitates. The relationship of precipitation kinetics to the C curves and

the influence of the various precipitates on mechanical properties and NDE

behavior is discussed.
iii

One dimensional heat flow calculations for the cooling of aluminum plates

of various thicknesses were carried out for three models of heat transfer,

viz. (a) symmetric cooling of the plate from both top and bottom surfaces,

(b) asymmetric cooling of the plate from the top surface only with an insulated

bottom surface, and (c) symmetric cooling of the plates for a specified time

followed by an abrupt reduction of the heat transfer coefficient at the bottom

surface to zero (insulated surface). The temperature-time curves for various

cooling conditions were combined with C curve data to calculate plate properties,

e.g., yield strength and hardness, as a function of position in the plate.

Such calculations for symmetric cooling are in general agreement with property

variations observed in as-received and properly heat treated plate. The minimum

properties expected under the "worst" quench malfunctions were also predicted

as a function of plate thicknesses.

Results of a Round Robin to determine the inter-laboratory precision

in eddy current conductivity and hardness measurements on a series of 2219

aluminum alloys heat treated to various conditions are discussed.
1v

table: of contents

Page No

.

I. INTRODUCTION I

II. STUDIES ON AS-RECEIVED PLATES 3

III. SOLIDIFICATION-SEGREGATION STUDIES 7

1. Microsegregation in Cast 2219 Aluminum Alloy 9

(a) Calculation of Microsegregation for 9

Al-Cu-Mn-Fe-Si Alloy System

(b) Second Phase Particles Formed During 12

Solidification of 2219 Aluminum Alloy

2. Macrosegregation in Cast 2219 Aluminum Alloy 15

(a) DC Cast Ingot 15

(b) Macrosegregation in Laboratory Cast Ingot 17

3. Thermomechanical Treatment and Evaluation of 19

Laboratory Ingot

IV. DETERMINATION OF C CURVES 21

1. Thermomechanical Treatment 22

2. Effects of % Stretch and Aging Treatment on Properties . . 23

3. Mechanical and Electrical Measurements 24

4. Measurements on As-Received and Reprocessed 2219-T87* ... 26

Plate

5. Measurements After Solution Heat Treatment and 27

Pre-Aging

6. Measurements After Stretching 27

7. Measurements after Final Aging . 28

8. Calculation of C Curves 29

9. Discussion 32

(
V

Page No.

V. ELECTRON MICROSCOPY STUDIES 41

1 . Experimental Procedure 43

2. Results 46

(a) Solutionized Structure 46

(b) Stretched and Aged Structure 48

(c) Microstructure After Quench Treatment 51

3. Discussion 56

VI. HEAT FLOW - PROPERTY PREDICTIONS 62

1 . Heat Flow Model 62

2. Heat Flow Calculations and Property Predictions 63

(a) Symmetric Cooling 64

(b) Asymmetric Cooling 65

(c) Abrupt Variations in Rate of Heat Extraction .... 66

From The Bottom Surface

3. Summary of "Worst" Property Predictions . 67

VII. ROUND ROBIN RESULTS 69

1. Samples 69

2. Equipment 70

3. Results 71

4. Discussion 73

VIII. CONCLUSIONS 75

1. As-received Plate 75

2. Solidification Segregation Studies 75

3. C-Curve Determination and Relationship Between 76

Mechanical Properties and Conductivity

4. Electron Microscopy Studies 77

5. Heat Flow Calculations - Property Predictions 78

6. Round Robin Results 79
Vi

Page No.

APPENDIX 80

ACKNOWLEDGEMENT 35

REFERENCES 86

TABLES . 88

FIGURES . . 127

\
1

I. INTRODUCTION

This Is a comprehensive technical report of our investigations in the past

eight months on 2219 aluminum alloy. The aim of this work was to develop

specific relationships between process variables used during casting, working

and heat treatment of the alloy, and the resulting microstructures and properties

including eddy current conductivity and hardness nondestructive evaluation (NDE)

responses.

The work was initiated at the National Bureau of Standards at the request

of the National Aeronautics and Space Administration. It was motivated by

government and aerospace industry concerns on the possibility that substrength

aluminum alloys may have been used in aircraft and space vehicle structures (1 )

.

These concerns originated from the discovery of "soft" spots'^ in an anodized

2124-T851 aluminum alloy machined part in June 1979. The part was machined from

a n. 14 cm* (5.5 inch) thick plate of the alloy produced in the Reynolds Metal

Company McCook Plant in Chicago, Illinois. The "soft" spots were apparently

due to improper processing of the plate (1). Furthermore, it ^Ifas established

that the same plant was producing a variety of other aluminum alloy plates including

the 2219 aluminum alloy which was the subject of this investigation. Serious

concerns were also expressed about the viability of test techniques used to find

suspect metal (2)

.

Specific aims of our investigation included the following:

1. To establish the processing conditions and mechanisms responsible

for the occurrence of "soft" spots;

2. To establish direct correlations between process variables and the

composition and microstructures of the plates;

t "Soft" spots denote areas of a plate with mechanical properties below

Federal Specifications.
3.

To determine the relationships between composition, microstructure

and the mechanical properties, hardness, and electrical conductivity of the

2

plates;

4. To develop correlations between electrical conductivity and hardness

and tensile properties for a wide range of metallurgical microstructures for

future use in the development of accurate specifications for 2219 aluminum

alloy plates; and

5. To develop predictive heat flow and time-temperature precipitation

models in order to determine the ranges of possible degradation of properties

due to improper processing conditions.

The investigations carried out were reported in detail in separate monthly

reports. This report covers all our investigations on 2219 aluminum alloy. In

the following, we describe details of our work in the following areas:

1. Studies carried out on as-received plates of 2219 aluminum alloy;

2. Solidification - segregation studies;

3. Determination of time-temperature precipitation diagrams, i.e. C curves,

and the relationships between mechanical properties and NDE responses;

4. Electron microscopy studies done on a wide range of metallurgical

microstructures produced, and

5. Predictions of heat flow conditions during malfunctions of the quench

from the solution heat treatment temperature and the resulting

mechanical property degradations.

6. Results of a Round-Robin for hardness and conductivity measurements

conducted on a set of 2219-T87* aluminum alloys.
II. STUDIES ON AS-RECEIVED PLATES

Four sets of 2219 aluminum alloy^ plates were used in this investigation.

They were:

1. A 12.7 cm (5 inch) thick plate in the T851 temper‘d obtained

from NASA (Reynolds Lot No. 7950777-DI).

2. A 0.635 cm (1/4 inch) thick plate in the T87^ temper"*^

obtained from Martin Marietta (Reynolds Lot No. 7430252-A).

3. A 0.635 cm (1/4 inch) thick plate in the as-fabricated F

temper obtained from Reynolds Metals and identified with

the Lot No. 7952505-E.

4. A 3.81 cm (1 1/2 inch) thick plate in the T851 temper

obtained from NASA Goddard. This plate was originally purchased .

from Generation Metals and was designated by the No. 313-812.

The mill source of this plate is not known and it was primarily

used for casting of some small samples for preliminary examination

of the as-cast structure of the alloy.

While all the plates noted above were used in the different portions

of this study, the primary work on the thermomechanical treatments was

carried out on the 0.635 cm thick plate in the T87* temper. On the

other hand, it was expected that across thickness variations in properties

due to macrosegregation in the original direct chill (DC) cast ingot or normal

t The composition of 2219 aluminum alloy according to ASTM Spec. B211 (or

QQ-A-250/30) is 5. 3-6. 3 ^t% Cu. 0.20-'0.^0 wt% Mn, 0.30 wt% Fe max,

0.20 wt" Si max, 0.02 wt^i Mg max, 0.10 hz% In max, 0.02-0.10 wifo Ti

0.05-0.15 wt^ V, 0.10-0.25 wc" Zr, others less than 0.15 wt" total.

The T851 heat treatment consists of solution heat treatment, a 2-1/4%

stretch and aging at 177®C for 13 hr.

tft T87* is a modified T37 therrriomechanical treaunent used by the Reynolds

McCook plant. It consists of a 5%, instead of a 7%, stretch followed

by a 16 hour aging treatment at '’-172®C. Hereafter, tnis Reynolas heat

treatment whicn was used in this program will be denotea as T37*.
thermal resistance of the plate during quench from the solution temperature

would be most pronounced in the thickest plate. Therefore, the 12.7 cm.

thick plate in the T851 temper was carefully examined for chemical,

microstructural and property variation across its thickness. The findings

from this study are presented below. Average hardness, electrical

conductivity and tensile properties of the thinner plates along with

their microstructures were also determined. These findings will be

discussed in the appropriate subsequent sections of this report.

The data obtained for the composition, hardness, conductivity and

tensile properties of the 12.7 cm thick plate are shown in Figures 1 and

2. These data essentially establish the maximum variations in properties

due to the macrosegregation remaining in the plate from the original DC

cast ingot and the normal variation in cooling rate experienced during

quench from the solution heat treatment temperature. The first plot in

Figure 1 shows that there is approximately 0.6 wt% variation in copper

content across the plate. This was determined by molecular absorption

spectrometry (wet chemistry). The abrupt changes in copper content at

the edges of the plate are due to the depleted region (negatively segregated

region) next to the chill face in the original ingot. The scalping

apparently removed the positive chill face segregation leaving some of

the depleted region intact which ended up in the plate. The negative

segregation at the plate centerline is due to the same type of segregation

noted in the DC cast ingot”.

The variation of the composition of copper and other alloying

elements was also determined by emission spectroscopy by the Inorganic

Analytic Research Division at NBS. Table I summarizes the maximum and

minimum values for each element obtained across the 12.7 cm thick plate.

tMacrosegregation across a DC ingot of 2219 aluminum alloy cast at the

McCook plant is shown in a subsequent section.
4-

lU

5

The copper variation across the plate determined by emission

spectroscopy agrees within experimental error with the wet chemistry

results. The Fe, Si, Zn, and, to a lesser degree, Mn profiles across the

thickness have the same general shape as the Cu profile with maximum and

minimum values given in the Table I. On the contrary, the Ti and V profiles

have their maximum at the center. The Zr, Ni and Mg profiles are relatively flat.

This behavior correlates well with the equilibrium partition coefficient,

k, for these alloying additions in A1 as determined from the binary diagrams.

Elements in the first group have partition coefficients less than one

whereas elements in the second aroup have coefficients areater than one.

The Rockwell hardness and conductivity, !5IACS (percent International

Annealed Copper Standard), measurements were made across the plate thickness.

The hardness was measured according to ASTM E-18 on a Wilson bench Rockwell

hardness tester. The conductivity was measured both on a portable Super Halec

Eddy Current Instrument"*", and on the NBS conductivity bridge described in a

later section. While minor variations were noted in the absolute measured

values between the two instruments, the trend shown in Figure 1 is a

representative one.

This instrument is manufactured by Hocking Electronic Ltd. in St. Albans,

ngland. All references to commercial equipment in this report are for

identification purposes only and in no way constitute any endorsement or evaluation of the relative merits of sucn equipm.ent.
The following conclusions could be drawn from the data on Figures 1

and 2. First, the variations in hardness and tensile oroperties can be

ascribed to the changes in cooling rate across the plate during the

quench and to the fact that the center of the plate did not experience

as much mechanical deformation as the outside to break-up the segregated

as-cast microstructure of the ingot:. Second, variations in electrical

conductivity, especially the abrupt variation near the surfaces of the

plate, may also be influenced by changes in copper composition in these

locations. This raises an important question regarding the effect of

alloy composition on electrical conductivity.

t The results of Section III indicate that copper variations of the order

seen in this as-received plate do not significantly affect mechanical

properties obtained after heat treatment.
III. SOLIDIFICATION-SEGREGATION STUDIES

Engineering alloys, such as 2219 aluminum alloy, solidify over a range

of temperatures and liquid concentrations. As a consequence, the elements

(such as copper) that are combined to make up the alloy of a given nominal

composition segregate during solidification. Segregation in cast ingots,

such as semi -continuous Direct Chill (DC) cast ingots of 2219 aluminum alloy,

can generally be divided into two categories: long range segregation

(macrosegregation), and short range segregation (microsegregation). Macrosegregation occurs over distances approaching the dimensions of an ingot-from

chill face to centerline in DC cast ingots. Microsegregation on the other

hand, occurs on the dendritic scale-on the order of 1/100 to 1/1000 of a

centimeter in the ingots in question.

Figure 3 shows the copper composition variation across the short

transverse direction of a DC cast ingot from the Reynolds McCook plant.

The ingot was not scalped. This figure indicated that even heavy scalping

will not remove the compositional variation. It does end up in the ingot,

if only at the center. Furthermore, very long homogenization heat

treatments at high temperatures are not effective in eliminating the

concentration gradients. Such segregation may effect the heat treatment

response of the alloy and its properties including responses to non-destructi

evaluation techniques used for quality control.
3

The second type of segregation, microsegregation, reveals itself, for

example, when the cast structure is etched by chemical reagents. It manifests

itself as alloy element concentration gradients across dendrite arms. The

regions between dendrite arms are usually rich in solute elements, contain

equilibrium and/or non-equilibrium second phases and microporosity. The

important influence of this type of segregation and the spacings, (dendrite

arm spacings), over which it occurs, on the properties of castings and wrought

materials produced from cast ingots is now well documented. A detailed

quantitative understanding of the variation in composition, of an alloy

during freezing (solidification "path”) and the resulting microsegregation are

also prerequisities to the successful quantitative analysis of the large

scale segregation (macrosegregation).

In this program we have undertaken a comprehensive experimental and

theoretical study aimed at establishing:

(a) The degree of micro- and macrosegregation that can occur in

as-cast ingots of 2219 aluminum alloy, and

(b) The influence that these segregations may have on both the thermomechanical treatment response of the alloy and its properties

including non-destructive measurements used for quality assurance.

These experimental studies were carried out on both a DC cast ingot

received from the Reynolds McCook plant and various smaller ingots cast in

our laboratories under controlled conditions.
9

1 . Microseqreqation in Cast 2219 Aluminum Alloy

A series of calculations and experiments have been performed to determine

the phases present in cast 2219 aluminum alloy with the ultimate aim of

calculating the degree of micro- and macrosegregation and identifying the

second phases present in the as-cast. ingots . Such segregation may have significant

effects on the heat treatment response of this alloy, and its properties, including

non-destructive evaluation techniques used for quality control.

(a) Calculation of Microsegregation for Al-Cu-Mn-Fe-Si Alloy System

Calculation of expected microsegregation for the n component alloy was

performed using the assumption of local equilibrium at the interface, complete

diffusion in the liquid phase, no diffusion in the solid phase and no fluid

flow in the interdendritic "mushy" region. During solidification of primary

a-aluminum, the situation is governed by (n-1) differential equations (3)

‘df.

dC

^ — i = 1, ...n-1

Li

1-k'^ C .

(

1 )

where f^^ is the weight fraction liquid, C^^^ is the liquid concentration of the

i alloying element, and k“ is the i equi 1 ibrium partition coefficient

for the solidification of the a-aluminum phase. In general, k? is a function

of Cj^2» ••• ^L(n-l)’ because the tie lines of this mul ti -component phase

diagram are not known we have assumed that k^ is constant and is determined

from the binary diagrams of aluminum with each alloying addition.

Solution to equation (1) in this case is:

( 2 )
10

where is the original composition of the i ^ component and is the

weight fraction solid (1-fj^). We calculate this solidification path vs

f^) to determine at what fraction solid the interdendri tic liquid becomes

saturated with respect to a second solid phase, i.e., when the solidification

path encounters a multivariant eutectic (or peritectic). After this point,

the solidification is governed by a different set of differential equations (3)

.

Present interest in 2219 aluminum alloy seems to require the examination

of the Al-Cu-Mn-Fe-Si quinary system. Other elements are present in small

quantities as grain refiners or impurities and have been neglected. This

choice is reasonable since most phases present in low Mg aluminum alloys are

contained in this system. Values for k? are shown below.

Equilibrium Partition Coefficients for

Solidification of Primary a-Aluminum Phase

Al-Cu 0.17 A

Al-Mn 0.95

Al-Fe 0.02

Al-Si 0.13

As an example. Table II shows the calculated solidification path (concentration

of the interdendri tic liquid as a function of f^) for an alloy Al-6.3 wt% Cu0.3 wt/o Mn-0,2 wt% Fe-0.1 wt% Si (Note max levels in the nominal alloy composition on Fe and Si are .3 and .2 wt% respectively).
n

To examine the solidification "path" in the five component phase diagram

is difficult and can only be done approximately. Fortunately, there are no

compounds in this system which do not appear in the ternary subsystems (4).

Many possibilities exist, depending on the initial alloy composition, for the

formation of second phases in the interdendritic region. If we examine the

solidification "path" (Table II) in various ternary system combinations of

these different components these possibilities become apparent. In Figure 4

are shown the solidification "paths" plotted in the Al-Cu-Mn, Al-Cu-Fe and

Al-Cu-Si ternary systems.

In the absence of Fe and Si the solidification "path" intersects the

monovariant eutectic trough of L -* a-Al+CuAl^ at f^ = Q.86. Hence in this

ternary system CuAl^ is the second phase to form and the third phase to form

would be Cu2Mn2Al2Q by way of the ternary eutectic L ^ a-Al+CuAl2+Cu2Mn2Al ^gIn the Al-Cu-Fe ternary system, the solidification "path" would intersect

the monovariant eutectic trough L ^ a-Al+Cu2FeAly at = 0.73. Hence, in

this case Cu2FeAl^ is the second phase to form and the third phase to form

would be CUAI2 by way of the ternary eutectic L ^ a-Al+Cu2FeAly-i-CuAl2-

In the Al-Cu-Si ternary, the solidification "path" would intersect the

monovariant eutectic trough L ^ a-Al+CuAl2 at f^ = 0.36. Hence CUAI2 would

be the second phase to form and the third phase to form would be Si by way of

the ternary eutectic L - ct-Al+CuAl2+Si

.

From these three systems, we note that the eutectic L ^ a-Al+Cu2FeAl

is encountered at the lowest volume fraction solidified, and hence it seems

reasonable that Cu2FeAly is the second phase to form in the quinary alloy.

Additional evidence for this is found in Figure 5 which shows a projection of

the quaternary tetrahedron Al-Cu-Fe-Si into the Al-rich corner (4). The
12 1

coordinates of this diagram are relative percentages of Fe, Si, and Cu. In

this figure a-aluminum is always present and hence regions represent the

solidification of two solid phases and lines represent the solidification of

three solid phases (ternary eutectic) etc. Examination of the compositions

reached in the interdendritic liquid show that Cu

2FeAly is the second phase

to form. During the subsequent freezing of a-aluminum and Cu

2FeAly the

liquid composition most likely moves toward the line representing the ternary

eutectic L a-Al+Cu

2 FeAly+CuAl2

. Examination of this quaternary diagram is

important because it excludes the possibility of either (Mn,Fe)

2

Si

2Alg or

(Mn,Fe)

2

Si

2

Al -|2 being the second phase to form. Such a conclusion might

have been reached by examining the Al-Fe-Si or the Al-Mn-Si ternary systems alone.

In this analysis, we have for the most part neglected Mn due to its relatively

high equilibrium partition coefficient.

(b) Second Phase Particles Formed During Solidification of 2219 Aluminum Alloy

The major second phase particles formed during solidification were

identified using differential etching, microprobe analysis techniques and

electron diffraction. Samples from a semi-continuous DC cast ingot and from

two laboratory ingots were examined. The DC cast ingot was obtained from the

Reynolds McCook plant through their Research Laboratory in Richmond, VA. The

section was marked 221 9-1 3402- 9B. The laboratory ingots were cast from two

lots of 2219 aluminum alloy plate: 3.81 cm (1-1/2 inches) thick from NASA

Goddard and 12.7 cm (5 inches) thick from NASA Marshall

t Average composition of the NASA Marshall 12.7 cm thick plate of 2219

aluminum alloy (Reynolds Lot No. 7950777-01) determined by emission

spectroscopy is 6.3 wt% Cu, 0.36 wt" Mn, 0.23 wtia Fe, 0.07 wt" Si,

0,12 wt% Zr, 0.07 vit% V, 0.03 v^t% Ti, 0.03 wtii Ni , 0.01 wt" Mg, and

0.03 wtio Zn.

I
13

A sample of 2219 aluminum alloy from NASA Goddard was melted and solidified

in a graphite crucible with a cooling rate of approximately 0.4 K/s. On

cooling, the start of primary solidification occured at 644 °C and a eutectic

arrest occurred at 543 °Z . These temperatures can be considered accurate to

within about ± 5 °C.

Typical as-cast microstructures of the alloy in optical and SEM micrographs

are shown in Figures 6 and 7. For this particular alloy, only three phases

appear to be present in the cast microstructure. The aluminum solid solution

() plus two phases which occur along with the a-phase in the interdendri tic

regions. The rounded irregular interdendritic phase is CuAl^ and the bladelike

phase is Cu^FeAl^ which is sometimes referred to as 3-AlCuFe. These findings

are in line with the theoretical predictions summarized above. Phase identification was made based on the known morphology of the phases occurring in

aluminum alloys (5) known etching response of the phases, electron microprobe

analysis, and electron diffraction.

Table III surmiarizes the etching response determined on cast 2219 aluminum

alloy. The etching response is somewhat different than published elsewhere

() and may reflect the presence of Mn in 2219 aluminum alloy.

Electron microprobe analysis was performed on the phases in cast 2219

aluminum alloy by the Center for Analytical Chemistry at NBS. The analysis

was performed in the energy dispersive x-ray spectrometry mode with

composition values derived with the NBS theoretical matrix correction FRAiMEC (7).

Table lY gives examples of microprobe results. The quantitative analysis differs

somewhat from exact stochiometry but the composition range of Cu2FeAly is known

to vary between 12-20 Fe and 29-39 wtiJ Cu (3).
14

Transmission electron microscopy, TEM, was applied to the study of the

as-cast structure. The specimens for TEM were removed from a 10 to 1 reduced

cross section laboratory ingot cast in this program. A description of this

ingot is given in the next section. The details of specimen preparation for

TEM and the methodology used in the analysis is presented in a subsequent

section under electron microscopy studies.

Figures 8 to 10 show TEM micrographs and selected area diffraction

patterns which provide positive identification of the rounded particles as

CuAl^ (0 phase) and the bladelike particles as the Cu

2

FeAl^ phase. The dark

interdendritic phase in Figure 8 is principally 0-CUAI

2

. An example of the

0-CUAI

2 phase from another region is shown in Figure 9, together with an

electron diffraction pattern which provides positive identification of this

phase. The phase adjacent to 0-CUAI

2

is a-Al . An example in which the

Cu

2 FeAly phase was idenitified is shown in Figure 10; again the diffraction

pattern agrees with the known tetragonal structure- of this phase.

The nature of the row of small plate-like particles present along the

boundary separating the two adjacent dendrites in Figure 8 was not established.

However, the diffraction pattern could not be rationalized with either the

structure of Cu

2 FeAly or 0-CUAI2

.

Regions within the dendrites were also examined for the presence of

precipitates. Bands of faintly visible particles can be seen in Figure 8.

On close examination, these particles were found to be 0 ' precipitates'^. An

example showing the three different {001} habit variants of 0

' is shown in

Figure 11, The 0 ' precipitates were found to be associated with subboundaries

such as those shown in Figure 12, and probably formed there during cooling in

the solid state. Many of the randomly scattered dislocations visible in

See Section V for a detailed discussion of the 0, O', and 0 " phases.

f
15

Figure 12 were almost certainly introduced during specimen preparation. The

0* precipitates did not occur in association with these dislocations.

Particles other than o' were occasionally found within the dendrites. These,

however, were probably second phases not associated with the primary solidification

process. Large numbers of intragranular particles, comparable to those seen

in processed plate materials in the solution heat treated and quenched state

discussed later, were not observed within dendrite regions of the ingot specimen.

2. Macroseqreqation in Cast 2219 Aluminum Alloy

A series of experiments and measurements has been performed to determine

the degree of macrosegregation in semi-continuous DC cast and laboratory cast

ingots of 2219 aluminum alloy. The former gave an indication of the maximum

composition variations expected in the final plate product while the latter

was used in the preparation of control specimens to establish the effect of

composition on measured NDE responses.

(a) DC Cast Ingot

A section of as-cast 2219 aluminum alloy was obtained from the Reynolds

McCook plant through their Research Laboratories in Richmond, Virginia. The

section was marked 221 9-1 3402- 9B. It extended from the chill face to the

centerline of the casting in the short transverse direction. Measurement of

macrosegregation was performed in a direction perpendicular to the chill face

as shown in the inset of Figure 3.

Chemical analysis for Cu was performed using two methods, x-ray fluorescence

using standards of Al-Cu alloys and wet chemistry. The latter was performed

by the Center for Analytical Chemistry at NBS by atomic absorption spectrometry

.

Both methods yielded similar results. The wet che.mistry data is shown in

Figure 3 and should oe considered accuraie to + 0.04 wt%.
16

As seen in Figure 3, extremely high positive segregation is noted at the

chill face vit% Cu) followed by a negative segregation region that extends

almost 2.5 cm (1") into the ingot. The minimum composition (-^4.7 wt% Cu)

occurs at '^^0.6 cm from the chill. A relatively uniform composition region

('^^6.4 wt%Cu) extends from ->^3 cm to 18 cm from the chill followed by a region

of negative segregation at the ingot centerline.

This composition profile can be readily correlated to that found in the

as-received heat treated plate of Figure 1. The outermost surface of the DC

cast ingot was scalped prior to the plate forming operation leaving some of

the negatively segregated region which ended up at the top and bottom surfaces

of the plate. The negative segregation at the ingot centerline is of essentially

the. same magnitude as that found in the plate.

The main phases present in this ingot are the same as that reported in

the previous section on cast 2219 aluminum alloy; namely, a-Al solid solution,

CuAl^ and Cu^FeAl^. Figure 13 shows an SEM view of the interdendritic eutectic

phases in this ingot. The solidification "path" described previously applies;

namely, primary solidification of a-Al followed by the eutectic L ^ a-Al+Cu2FeAly

and finally the ternary eutectic L a-Al+Cu^FeAly+CuAl^.

Figure 14 shows micrographs from the ingot taken at the chill face, 0.5

cm from the chill face and 1.7 cm from the chill face. These positions

correspond to approximately 18, 4.7 and 6.1 wt% Cu as documented in Figure 3.

These micrographs show cored dendritic a-Al plus differing amounts of interdendritic “eutectic". In agreement with their compositions, the material

near the chill face has the highest fraction of interdendritic eutectic (or

particles oi^ CuAl^ and Cu2peAly) whereas the material 0.5 cm from the chill

has the least. The material 1.7 cm from the chill has an intermediate fraction

of “eutectic" and is fairly typical of the rest of . the ingot except near the

centerl ine.
17

(b) Macrosegregation in Laboratory Cast Ingot

Following the work of Mehrabian and Flemings on macrosegregation in

multicomponent systems^^^ a special geometry unidirectional ingot was cast

with 2219 aluminum alloy to demonstrate the mechanisms responsible for the

positive and the negative macrosegregation noted in the DC cast ingot and to

obtain controlled composition samples differing from the nominal. These

samples have been used for thermomechanical treatments and nondestructive

evaluation.

The geometry of the casting is shown in the inset of Figure 15 and

employs a reduction in area of approximately 10 to 1 to cause macrosegregation.

The bottom section of the casting is 11.8 cm square and 9.5 cm high while the

top section of the casting is 3.7 cm square and 12 cm high. An investment

mold of plaster was preheated to 540 °Z and placed directly on a water cooled

chill block. The mold has an open bottom so that molten metal came into

direct contact with the chill. This, coupled with the preheated mold,

guaranteed directional solidification of the ingot. The mold was filled with

molten 2219 aluminum alloy (obtained from NASA Marshall as 12.7 cm (5") thick

plate) at about 700 after being degassed with hexachloroethane. The

casting was analyzed for average composition variation (macrosegregation) in

the direction perpendicular to the chill. The variation in copper, iron and

manganese content determined by atomic absorption spectrometry as a function

of distance from the bottom chill in the as-cast ingot is shown in Figure 15.

As expected from previous studies of macrosegregation noted above, high

positive segregation ('>.7.3 Cu) is observed at the chill face while negative

segregation ('>.3.6 wt% Cu) occurs in the region of the cross section change.

Iron, and to a lesser extant manganese, also show a high level at the chill

face, drop to a minimum near the cross section change and rise again in the

rest of the ingot. This similarity of shape of these profiles with the
18

copper profile is an indication that the equilibrium partition coefficients

for Cu, Fe and Mn (0.17, 0.02, and 0.95 respectively) are all less than one.

Because the partition coefficient for Mn is close to one, macrosegregation of

Mn is less than Cu or Fe.

Chill face and cross section change segregation both result from the

flow of segregated interdendritic liquid to feed solidification shrinkage.

It should be noted that the laboratory ingot exhibits a lower positive chill

face segregation and no adjacent negative segregation compared to the DC cast

ingot. The occurrence of these phenomena near the chill face of the DC cast

ingot can be readily ascribed to the formation of an extensive air gap which

results in the abrupt reheating of the ingot surface during solidification

and the exudation of the solute rich interdendritic liquid from the adjacent

region. On the other hand, the negative segregation at the DC ingot center

line and the section reduction of the laboratory ingot are due to the extensive flow of interdendritic liquid from the hotter to the cooler regions

of the ingots at these locations.

The phases present in this ingot are the same as those described above

for the DC cast ingot. Figure 16 shows the three phases present. Similar

results are obtained in this ingot regarding the variation of the fraction of

interdendritic "eutectic” as the copper content changes with distance from

the bottom chill surface.

The relative levels of Cu, Fe and Mn are also important because they are

the major components which determine the phases present as second phases along

with a-Al in cast or heat treated 2219 aluminum alloy. For example, samples

cut from different parts of this ingot and processed in the T87* condition

(see next subsection) contained different amounts and types of inclusions.
19

A second laboratory ingot of 2219 aluminum alloy with a 10 to 1 reduction

in cross section was also cast in a manner identical with the first ingot

with eight thermocouples inserted through the mold at different distances

from the bottom chill face. Figure 17 shows the temperature- time curves for

the eight thermocouples and the distance from the chill face of each. The

liquidus and solidus temperatures for this alloy are approximately 644 (+5)

and 543 (+5) °C respectively and hence, from these curves the local solidification

time as a function of position has been determined. This data will be used

to theoretically calculate expected macrosegregation in this ingot for comparison

with the experimental composition data presented in Figure 15.

3. Thermomechanical Treatment and Evaluation of Laboratory Ingot

The effect of variations in alloy composition due to macrosegregation on

the heat treatment response of 2219 aluminum alloy and its properties including non-destructive measurements used for quality assurance has been

evaluated using samples taken from the reduced cross section laboratory

i ngot.

Samples, ^3.7 cm square and "-1.3 cm (->-1/2") thick in the solidification

direction, were cut from the ingot at different distances from the bottom

chill face to obtain specimens with differing compositions. The samples, of

course, contained composition gradients through their thickness, but were

relatively uniform in perpendicular directions due to the unidirectional

solidification. As a reference point, eddy current measurements were conducted

on as-cast samples. Measurements were made with the coil on the surfaces

which were perpendicular to the solidification direction. The conductivity

along with the previously determined copper content is shown in Figure 18.

All electrical conductivity measurements were made on the MBS conductivity

bridge as described elsewnere in shis report.
20

These data indicate the same trend as observed in the as- received 12.7 cm

(5 inch) thick plate described in the previous section; i.e., increases in

copper content correspond approximately to decreases in conductivity.

The samples were then thermomechanically treated as follows:

(a) homogenization heat treated for 48 hours at 535 ®C,

(b) hot rolled at 440 ®C to 1/4 of their initial thickness (0.32 cm,

1 / 8"),

(c) solution heat treated at 535 °C for 75 minutes,

(d) stretched 5% and aged at 172 °C for 16 hours^.

Hardness and electrical conductivity measurements were carried out on

both surfaces of these 0.3 cm thick samples. In Figures 19 and 20 are plotted

hardness and conductivity respectively as a function of the original distance

of these surfaces from the bottom chill face along with the copper content. Not

until the copper content drops below -^5.5 wt?i does the hardness drop significantly.

On the other hand, the variation in electrical conductivity appears to follow

the same general trend as that established for the as-cast structure in

Figure 18. Note that the variation in copper content shown in Figures 15 to

17 is that obtained in the as-cast ingot. Some averaging of variations in

composition has occurred during the rolling operation which manifests itself

in the conductivity data scatter noted in Figure 20.

Tensile tests were conducted on the thermomechanically treated samples.

Figure 21 shows tensile and yield strength of these samples as a function of

the original distance from the bottom chill along with the Cu content.

Tensile data beyond the 14 cm point is unreliable due to porosity present

near the top of the casting. Again notable reduction of properties correspond

to reductions in copper content below '^^5.5 wt".

t This is the modified T87 treatment practiced at the Reynolds McCook plant

which is referred to herein as T87* in this report. No interrupted quench

experiments were performed on the cast samples.
21

IV. DETERMINATION OF C CURVES

A comprehensive thermomechanical treatment program was undertaken to

provide samples for establishing the effect of process variables on the

microstructural , mechanical, and NOE properties of 2219-T87* aluminum alloy,

and to establish TTT curves (C curves) that could be used in assessing the

effect of various quenching treatments on the final properties of the

processed material.

The C curves are a family of C-shaped curves used to characterize the

effects of quenching on the final properties of the finished material. Their

use for aluminum alloys was pioneered by W. L. Fink and L. A. Willey (10). To

determine these curves, specimens are first solution heat treated and then given a

series of (nearly) isothermal anneals (referred to here as "pre-aging" treatments)"^

prior to cold working and the final low temperature aging. The final properties

are then measured and the effects of the pre-aging treatment are assessed. In

using’ the C curves, a "rule of additivity" developed by Cahn (11) is used. This

rule is also used in determination of the C curves but is much less important

4 there because the pre-aging is nearly isothermal.

The extent to which the "rule of additivity" is applicable to aluminum is not

yet completely verified. However, previous experience by Staley (12) indicates that

this rule can be applied with good approximation to some aluminum alloys. The

differences we note in the present study between the "sequence A" and "sequence B"

heat treatments of the 2219 aluminum alloy also gives some indication as to how

closely this rule is followed. We use the results on these two sequences in a

subsequent section to set limits on what might be obtained under "best" and "worst"

quenching conditions for a 2219-T87* aluminum alloy plate.

t The term "pre-aging heat treatment" is being used in place of the term

interrupted quench or slack-quench. Since the definition of these terms is not

firmly established, we use "pre-aging sequence A" (monotonic auench) and "pre-aging

sequence B" (quench with re-heat) herein.
22

1 . Thermomechanical Treatment

The treatments were carried out using, as starting material, the 0.635 cm

(1/4") thick plate of Reynolds 2219-T87* obtained from Martin Marietta. The

plate width was 1.22 m (4 ft.) and the plate length was 1.83 m (6 ft.). Three

samples of the plate were removed for chemical analysis 0.6 m (2 ft.) from the

plate end, one from each edge and one from the middle. These samples were

analyzed using emission spectroscopy by the Center for Analytical Chemistry at

NBS. Results of this analysis are shown in Table V.

The plate was then cut into bars approximately 2.5 x 17 cm with the long

axis parallel to the rolling direction of the original plate. A jig was

constructed to hold four bars for simultaneous heat treatment. The samples

were instrumented with calibrated thermocouples as illustrated in Figure 22.

Each set of specimens were then given one of two heat treatment sequences which

we refer to as sequence A and sequence B . These treatments, which are

identical to the T87* treatment except for the interrupt from the solution

heat treatment, consisted of:

(i) solution heat treat at 535°C for 75 minutes

(ii) sequence A alloys; direct transfer to salt bath

sequence B alloys; water quench followed by transfer to salt

bath (salt bath temperature was varied between 250®C and

475®C; time in salt bath was varied between 2 and 3600 seconds)

(iii) water quench

(iv) mechanically stretch to 5% permanent- strain

(v) age in air for 16 hours at 172®C.

The time-temperature profiles of these sequences are schematically illustrated

in Figure 23. Typical examples of time-temperature curves obtained for the

sol utionizing and pre-aging heat treatments are shown in Figures 24 and 25. Only

three of each group of four specimens were given the S% stretch and final aging.
23

Of these three, two were machined into the tensile test specimens illustrated

in Figure 26 . The surfaces of these tensile test specimens were milled to a

63 'Ljn finish or better.

2 . Effects of % Stretch and Aoinq Treatment on Properties

In order to assess the effects of % stretch and aging treatments on basic

mechanical properties of the 2219 plate materials, a short study was performed.

The values of the variables used in the study were the following;

Percent stretch: 0, 2-1/4, 5 and 7.

Aging treatment after stretching: (a) 16 hrs . at 172®C, (b) 13 hrs . at

177®C. Prior to stretching and aging specimens taken from the 0.635 cm (1/4")

thick plate were solution heat treated at 535°C for 75 minutes, then quenched in ice

water. After stretching and aging, flat tensile specimens were machined in

the longitudinal tensile axis direction.

The effects of % stretch and heat treatments (a) and (b) above are presented

in Figures 27 and 28. Both yield strength and ultimate tensile strength

increased with increasing % stretch; however, little improvement was observed

between 5 and 7 % for either aging treatment. The lower temperature, shorter

time treatment {(a) above) seemed to respond more to the 2-1/4% stretch than did

treatment (b) insofar as tensile properties were concerned.

The effects of % stretch on elongation and reduction of area were less

clear. While one might expect to see a decrease in ductility as strength level

increases, this was not marked in the case of elongation. If the single high

value at 7% stretch for treatment (a) is discounted, a slight decrease is indicated.

For reduction of area, on the other hand, the 2-1/4% stretch appears to give the

highest values.
24 I

Except for the fact that unstretched hardness values differed, hardness

data tended to follow the same trend as ultimate strength in that no appreciable

gains were noted once 5% stretch was reached. Aging treatments were differentiated

only at lower values of % stretch.

In summary, from the present study:

(1) there was no significant improvement in strength or hardness between

5 and 7% stretch. In fact, there was an indication that some loss of

ultimate strength and hardness occurred at the 7 % stretch for aging

treatment (a).

(2) With one exception, elongation tended to decrease as " stretch

increased.

(3) Reduction in area showed a maximum at 2-1/4% stretch, but considering

data scatter this effect was not sharply defined.

(4) The main differences between the two aging treatments studied were

seen in strength and hardness for the case of the 2-1/4% stretch.

3 . Mechanical and Electrical Measurements

The hardness and conductivity of all specimens were monitored before the

solution heat treatment, after the solution and pre-aging treatments, after

the 5% stretch, after the final aging treatment, and after machining into tensile

test specimens. Rockwell B hardness measurements were made according to ASTM E-18

on a Viilson bench model Rockwell hardness tester. Each time hardness was measured

two measurements were taken on the sample surface at a random location except

within 5 cm of the sample center and, for the tensile test specimens, outside the

gage. The yield strength (0.2% offset) and ultimate tensile strength were

determined on a calibrated Satec System Inc. Baldwin Model 60 CG Universal

Testing System.
25

On all samples after the final aging treatment, and on all samples after

machining into tensile test samples, measurements of electrical conductivity

were made using the NBS conductivity bridge. This bridge has extremely high

sensitivity and the signal to noise ratio is on the order of 2 x 10^.

Conductivity can be measured at any frequency between 5 kHz and 100 kHz. The

bridge was completed recently and its accuracy and precision are still being

evaluated. Changes of .01% lACS are clearly evident.

Due to the newness of the bridge, its full capabilities were not utilized

in the present tests. Instead it was operated as most commercial bridges

using a fixed frequency (10 kHz) for all measurements. To determine the

conductivity the bridge unbalance voltage when the coil was placed on the

samples was measured. The bridge output voltage is proportional to change

in impedance of the coil. This voltage was then related to the unbalance

voltage when the coil was placed on the standards, using a linear relationship.

The bridge was calibrated using two Boeing electrical conductivity standards

of 28.81 ± .28% lACS and 35.07 ± .35% lACS. These standards had their last

calibration in 1976.

The tests were done with the bridge being calibrated at the start and

finish of the measurements. The elapsed time between calibrations was

approximately 20 minutes. During this time span, no drift of the instrumentation

was evident. The temperature of the standards and test pieces was 23 ± .2®C.

To determine the conductivity of the test pieces a linear relationship was assumed

between conductivity and bridge unbalance. Due to the lack of recent calibration

of the calibration standards the conductivities of the test pieces should be

understood in a relative sense. The changes measured are accurately measured

with respect to the standards and are repeatable but should be understood only

as an indication of change and not in an absolute sense.
26

Conductivity measurements of each sample before treatment, after the

solutionizing and pre-aging treatment, and after the 5 % stretch were made

at 23 ± 1®C using a Hocking Electronics Super Halec model portable eddy

current instrument operated at 10 kHz with a. digital voltmeter attached to

the readout. Before each measurement, the readout was calibrated using three

reference samples of 37.8, 33.2 and 32.2 % lACS which were previously measured

on the NBS conductivity bridge. Although some loss of precision is unavoidable

with this procedure, the values obtained should be comparable to within

± 0.3% lACS with measurements made on the NBS conductivity bridge.

Data on hardness and conductivity measurement for all the samples subjected

to various heat treatments are listed in Table VI. Table VII gives the timetemperature data of the heat treated specimens which will be used later in the

determination of C curves. Table VII also summarizes the hardness (average of

the two measured values before machining) and conductivity after final aging,

the yield strengths, ultimate tensile strengths, percent elongation, and percent

reduction in area for each sample.

4. Measurements on As-Received and Reprocessed 2219-T87* Plate

Two hardness measurements were made on each of the 289 samples cut from the

as received 0.635 cm (1/4") thick plate of 2219-T87*. The average hardness

obtained was 78.4 HRB with a standard deviation of 1.0 HRB . One conductivity

measurement was made on each of the samples. The average conductivity obtained

was 33.6% lACS with a standard deviation of 0.3% lACS.

The longitudinal and transverse yield strengths (0.2% offset) and ultimate

tensile strengths were measured on twelve samples cut from the same plate. The

longitudinal specimens gave a yield of 56.4(5) ksi and a tensile of 69.8 ksi

.

The transverse specimens gave a yield of 56.4(7) ksi and a tensile of 70.9 (7) ksi.

(Numbers in parentheses represent error in last digit at the one sigma level.)
27

About twelve samples from the as-received 2219-T87* were reprocessed to the T87*

with no pre-aging treatments.' These reprocessed samples gave an average

hardness of 78.1 HRB with a standard deviation of 1.1 and an average

conductivity of 33.6 % lACS with a standard deviation of 0.4% lACS. These

reprocessed samples gave a yield strength of 55.4(8) ksi and a tensile strength

of 69.4(8) ksi. These results show that the reprocessed 2219-T87* closely

achieves the mechanical and electrical properties of the original plate with

perhaps a small degradation (on the order of 1%) in the measured mechanical

properties

5. Measurements After Solution Heat Treatment and Pre-Aging

The hardness obtained after solution heat treatment and pre-aging is plotted as a

function of conductivity in Figure 29. In this Figure, sequence A and sequence

3 alloys are indicated by different symbols. It is seen that, within the scatter

of the data, the sequence A alloys fall on a regular sequence, whereas the

sequence B alloys do not. The sequence A data were least squares fitted to the

quadratic equation.

2

H = a + aTC + a«C (3)

0 12

where H is the Rockwell 3 hardness and C the conductivity in % lACS. The values

obtained for the constants were: a^ = -541, a-j = 3918, and a 2

= -0.648. The fit

gave a residual standard deviation of 3.1 hardness units. This least squares

curve and a scatter band (approximately 95% confidence level) are also shown in

Figure 29.

6 . Measurements After Stretching

The hardness obtained after solution treatment, pre-aging, and stretching is plott

as a function of conductivity in Figure 30. In this figure, sequence A and sequence

3 alloys are again indicated by different symbols. As for the case before stretching,

sequence A alloys fall on a regular sequence (within the scatter of the data),

whereas sequence 3 aiioys do not. 'when the sequence A alloys v/ere least squares
28

fitted to the quadratic equation (Equation (3)), the values obtained for the

constants were: a^ = -208, a^ = 19.5, and ^2 " -0.353, The fit gave a residual

standard deviation of 2.3 hardness units. The sequence A least squares fit and

a scatter band (approximately 95% confidence level) are also shown in Figure 30.

The dislocations introduced by the stretching result in an increase in

hardness and a decrease in electrical conductivity. In Figure 31, we plot the

change in hardness vs. change in conductivity. Mo trend or correlation is evident

from this plot. Upon stretching to 5% permanent strain the hardness appears to

increase, on average, about 18 HRB, and the conductivity to decrease, on average,

about 0.5% lACS.

7. Measurements After Final Aging

The hardness and conductivity data of Table VI after final aging are plotted

in Figure 32. In contrast to the measurements after preaging and after stretching,

sequence A and sequence B alloys now appear to follow the same trend. (In making

this plot, the hardness and conductivity measurements before and after machining

were averaged.) The data were least squares fitted to a quadratic equation

(Equation (3)). The values obtained for the constants were: a^ = -736,

a.| = 51.4 and d^2 ~ -0.811. The fit gave a residual standard deviation of 2.4

hardness units. The least squares fit and a scatter band (approximately 95%

confidence level) are also shown in Figure 32.

As described previously, when the samples were machined into tensile test

specimens, approximately 0.6 mm was machined from the surface. The hardness and

conductivity were measured both before and after the machining procedure. The

measurements after machining vs. those before machining are plotted in Figures 33

and 34, along with a linear least squares fit and scatter band. These measurements indicate that there is no detectable difference in either the hardness or

conductivity after machining the surface.
29

3, Calculation of C Curves

The data on hardness, conductivity, yield strength, tensile strength

and time-temperature history tabulated in Table VII have been used to

determine a set of C curves for both sequence A and sequence B alloys.

Following Evancho and Staley (13) and Cahn (11, 14), we have used the

following parameterization to represent the C curves: It is assumed that the

value of a resulting property, a, can be represented as

a = (a^ - 0^) exp(-<,^T^) + (4)

where a is the maximum achievable property, a is the minimum or "intrinsic”

value of the property achieved under the given conditions, is given by

0 dt

C^(T(t)) (5)

with t^ being the start of the quench from solution heat treatment temperature,

t the time to achieve a temperature less than about 120°C, and C (T) given by

w A

Cx(T) = <2 exp

K3K4

RT(k^-t)'

exp 1 —

RT

( 6 )

where :<2

, K^, K^, and are constants to be determined, T is the absolute

temperature, and is an arbitrary constant taken to be

'a - c

X 0

^m ' ^0

(7)

K, is chosen so that for t >1 , a is less than a so that t becomes a critical

• A X X X parameter for achieving some specified value cr. of the property in question.

X
30

To determine the parameters a^, K^, K^* *^4

* *^5 following

procedure was used:

(i) the temperature from SSS^C (the solutionizing temperature)

to 119®C is divided into 35 intervals,

(ii) the time, t^. , spent in each of the temperature intervals

is taken from a chart recorder and used to numerically

calculate the integral of Equation (5) according to

where is the average temperature in the interval, and

(iii) using an iterative, non-linear, fitting routine, values of

the parameters which minimize the least squares deviation

between measured and calculated values are obtained.

The computer program to do the least squares fit is listed in Appendix

A. This program was adapted from a non-linear least squares routine described

in detail elsewhere (15). The data input portion of the program as listed is

designed to read data in format shown in Table VII. A card with the word END on

it is required at the end of the list of temperature intervals and at the end of

all input data. Initial guesses are supplied by the user for the parameters

'^m* S’ “^o* other interactive input to search for a

set of values which minimizes the least squares deviation. Briefly, the operator

tells the program what combination of parameters to vary and what step size to

use in calculating derivatives. The program calculates the necessary partial

derivatives numerically, then sets up and solves a matrix equation and determines

new values for the parameters. If these new parameters actually reduce the least

square deviation, they are accepted. This procedure is continued until no further

reduction in the least square error can be obtained. If a successful fit is noz

obtained, initial parameters and step sizes are changed and anoiher attempt made.

n

(8)
31

The set of parameters obtained for the C curves for sequence A and

sequence B alloys are given in Table VIII. These C curves are represented

in Figures 35 through 42.

An interesting question related to these C curves is: to what

precision are the parameters determined? For purposes of comparing the fits

we define a quantity, e.s.d., called here the "estimated standard deviation",

by

e.s.d. *

where is the measured value of the property in question for the i^^ sample,

‘^ci

the calculated value, and N is the total number of samples. First, consider

the value of Kg. In Table IX, we show the effect of various choices on the other

parameters and on the estimated standard deviation for the hardness. There is

practically no effect on e.s.d. for values of Kg between 30,000 and 40,000. The

variation of the C curves obtained for three choices of Kg is shown in Figure 43.

These curves vary in minor details. We have chosen the value of 32,000 cal /mol

for Kg because it is close to the known activation energy for diffusion of copper in

aluminum, and because it can be used to give a consistent fit to all the sequence

A properties using constant values for Kg and K^ (as shown in Table VIII). When

the value of Kg is chosen at 32,000 and the other parameters are fitted, the effect

of varying one parameter only on the e.s.d. can be determined. This is plotted

in Figure 44 for e.s.d. from the sequence A data.

The set of values given in Table VIII for the C curve parameters can be

used to obtain relationships between the mechanical and electrical properties.

Since the C curves, for a given sequence, vary only on their value of Kg, these

relationships can be computed parametrically using a parameter Q such that each

property o is given by
(10)

fe)

+ a

where ^nd are the appropriate values for the property being

calculated. A series of such plots which display the correlations for both

sequence A and sequence B alloys are shown in Figure 45 through 50. These

plots also show the appropriate data and scatter bands (approximately 95%

confidence level). The scatter bands were obtained from a least squares

quadratic fit to all the data and represent ±2 residual standard deviations

from this fit. As an example, the residuals (difference between the data and

the fit) for the plot of yield strength vs. hardness are displayed in Figure 51.

Figure 52 shows a normal probability plot of the hardness residuals plotted in

Figure 51. This type of plot provides a graphical test of how well the residuals

follow a Gaussian statistical distribution - a straight line indicates a so called

normal (or Gaussian) distribution. The nearly straight line obtained and the

absence of gaps in the plot indicate that the data are consistent with a normal

distribution. The same test was applied to all the fits in Figures 45 to 50

with similar results.

9. Discussion

The C curves calculated above give a self-consistent description of the

measured variations in mechanical and electrical properties of 2219-T87* that

were produced by the quench procedures used here. Not only do the curves predict,

within the scatter of the data, the properties as a function of heat treatment,

but they can also be used to calculate the relationship between properties.

For example, Figure 48 compares the measured data with the C-curve predicted

relationship between ultimate tensile strength and electrical conductivity.

Although the correlations for both sequence A and sequence B alloys fall

within the scatter band, the two correlations are noticeably different. However,
33

note that the difference between sequence A and sequence B is less significant

at the higher tensile strengths. This trend is also true for the other

correlations as well.

If the time-temperature curve during the quench from the sol utionizing

temperature is known, the C curves can be used to predict the final properties

of the alloy if the "rule of additivity" is assumed. The extent to which

additivity applies to 2219 has not been fully tested. Previous experience

(12) with other aluminum alloys has indicated that it can be applied with good

approximation. The most important factor is the rate of temperature decrease

while the temperature is in the vicinity of the "nose" of the C curve. In

this respect, 2219 aluminum alloy is less quench sensitive than, for example,

7050. For 7050, the nose of the C curve lies at a lower temperature (see

Figure 53) where the time to reach this temperature would be longer for a given

heat transfer coefficient when compared with the temperature at the nose of the C

curve for the 2219 aluminum alloy. Also, for a sequence B type quench, the

temperature would be more likely to reach the nose of the C curve for 7050 than

for 2219.

The difference between the C curves for sequence A and sequence B is small

but significant. For example, using Figures 35 and 36 we can see that a sample

which spent 20 seconds at 420 °C during the quench would have a yield strength

of 51 ksi for sequence A, which would meet the minimum specification for a 7.6

an (3 inch) plate, but only 49 ksi for sequence 5. In the absence of further

data, the best method for applying the C curves would be to use the sequence A

curves if the time-temperature curve mcnotoni cal ly decreases from the

sol utionizing temperature and the sequence B curve otherwise. The C curves

presented in Figures 36 through -12 are probably somewhat biased towards shorter
34

critical times at temperatures above 475 ®C and below 250 ®C. This is not

considered a problem in applying these curves since the quench time spent at

these temperatures is usually much shorter than the critical times for most

heat flow conditions.

If we use the correlations presented in Figures 45 through 50 between

yield strength and ultimate tensile strengths which are specified by Federal

Specification QQ-A-250/30) and the hardness and conductivity we can construct

a table for 2219-T87* giving the minimum hardnesses and maximum conductivities

corresponding

—

to the specified minimum strengths as follows:

Tensile Strength Yield Strength

Thickness - Specified

minimum HRB % lACS

Specified

minimum HRB % lACS

inches ksi min. max ksi min; max.

0.020 - 0.249 64 72.6 34.3 52 74.0 34.2

0.250 - 3.000 64 72.6 34.3 51 72.6 34.4

3.001 - 4.000 62 70,2 34.8 50 71.2 34.7

4.001 - 5.000 61 69.0 35.1 49 69.7 35.0

However, care must be utilized in using such a table. The above refers to

Rockwell B hardness measurements made on a bench unit for full conformance to

ASTM E-18. Even under such controlled conditions there is considerable scatter

in the hardness measurements, generally greater than ± 1 Rockwell B hardness unit

at the one sigma level. This scatter is due in part to the measurement itself

and in part to inhomogeneity in the material over a size range greater than the

hardness indentation diameter.
35

When making measurements with portable units, which generally make smaller

indentations and, because of size limitations, cannot control test conditions

with the precision of a bench unit, hence, greater scatter in the hardness can be

expected. Ideally, enough hardness measurements would be made in a localized area

to determine both the mean and the variance in that area. Practically speaking, it

it generally required to make several, at least three, measurements in a localized

area and to use the mean of these measurements.

Converting the readings of a portable hardness tester to Rockwell B

units poses a separate problem. It cannot be considered satisfactory to

calibrate the portable tester with brass standards when using the tester on

aluminum. Since aluminum standards are not generally available, calibration

of a portable unit must proceed by measuring a range of aluminum alloy samples

on a bench tester according to ASTM E-18, then using these samples to calibrate

the scale of the portable unit, with a large number of measurements (at least

five) being made on each sample.

Although the conductivity measurement averages over a larger sample area

than the Rockwell 3 hardness measurements, considerable scatter in the measurement remains. Again, this scatter is due in part to the measurement itself and

in part to inhomogeneity in the material over a size range greater than the probe

diameter. Thus, for critical applications, it is also desirable to make several

eddy current measurements in a localized area and to use the mean of these

measurements. Calibration of conductivity measuring instruments is a critical

factor. Generally, the differences in conductivity can be measured with much

greater precision than absolute values. Figure 54 presents an example of this

problem, where the yield strength vs. conductivity curves determined by four

laboratories on different lots of material are compared.
36

Since the hardness and conductivity of plates are generally measured on

the surface, the degradation in properties from surface to center under normal

conditions of heat extraction due to only resistance in heat flow in the plate

itself must be taken into account. For example, for a 12.7 cm (5 in.) thick

plate using sequence A cooling, the yield strength in the center of the material

is as much as about 3 ksi less than the yield strength at the* surface. (This

assumes a plate of uniform composition.) Accordingly, to meet the specification

of a minimum yield strength of 49 ksi for a 12.7 cm plate, the hardness and

conductivity measured on the surface must correspond to those for a yield strength

of 52 ksi. For sequence B cooling, the surface to center degradation can be more

severe, up to about 6 ksi difference between the surface and the center of a 5

inch plate. These effects are considered in more detail in the next section.

Because of the poor inter-laboratory correlation between yield strength

and conductivity measurements seen in Figure 54 some further remarks on

the sources of error in conductivity measurements and on its usefulness

as an NDE tool for sorting out bad material are required.

Electrical conductivity measurements were made on the various types

of metal samples that are discribed elsewhere in the report. The greatest

number of measurements were made on samples which were approximately

5 to 6 mm thick, 25 mm wide, and 150 mn long. In order to insure the

highest accuracy of measurement all possible physical effects which might

cause error had to be evaluated. These effects could in general be

classified as coil-metal field interactions and temperature effects.

The coil-metal interactions can be further subdivided into lift-off

effects, edge effects and field penetration through the metal. The

errors due to field penetration through the metal are considered to

be negligible due to the thickness of the samples and the frequency
37

used (10 to 20 kHz). To Insure that no penetration error was present,

a test was run using a second coil as the detector. This coil was

placed on the metal so that it was concentric with the driving coil but

with the metal sample between the two coils. The bridge was then run

at its normal power level and the detecting coil was connected to the

detector of the system. No appreciable field could be detected even

at the highest levels of detector sensitivity.

Errors due to lift-off effects (changes in distance between the

coil surface and the metal surface) were made negligible by adjustment

of the phase of the bridge detector. The lift off compensation is

accurate as long as the separation distance between the two surfaces

is less than C.H nm. A test sample holder was constructed which held

the metal surface against the coil surface with a constant pressure

for all samples. This also insured that any distortion of coil geometry

due to the pressure would be the same for all samples.

Some test samples were measured immediately after the 5% stretch and

before the surface 'was machined. The surface of these samples vas slightly

mottled by the mechanical stretch. This could introduce some error due

to lift off or lift off related effects. Several coils of different

diameter, i.e., 12.7 irm and 6.35 mm were used to measure these samples.

No change in value could be seen at the lACS level using the two

coils. Thus it has been assumed that in this case the surface had no

effect on the measurement.

Errors due to edge effects are still in the process of being evaluated.

The sample width 'was 25.4 :titi and measuranents were made along the centerline of the sample. Initially tests 'were run moving the coil away from
the centerline until a change of 0.01% lACS was noted. These tests were

done using both coils. The data from these tests showed that the coil

need not be perfectly centered to achieve good measurements. It was

only at the end of the tests and after several discussions with others

in the field that it was realized that edge effect errors could still

exist and not be detected due to the symmetry of the test samples.

Further tests are now being done to characterize the error that might

be present in the measurement. It is thought that this error should be

less than 0.1% lACS.

Errors in the measurement due to temperature variation- were minimized

by keeping the test samples and the standards in a partially enclosed

area. Thus variations in ambient temperature were decreased at the

test site. The samples and the standards were kept in contact except

during the time an individual sample was being measured. Ambient temperature

vas monitored at a distance of 25 run from the side of the coil. The

sample holder eliminated any temperature variation that might be due to

human contact with the coil and being near the test samples. At random

intervals a test sample was monitored for several minutes to determine if

any temperature drift was occuring during the measuranent.

Errors due to drift of the instrumentation over the period of time

that it took, to do a series of measurements are considered negligible.

To test this assumption standard inductors were placed in the bridgecircuit replacing the coil. These standards were well insulated thermally

so that their electrical properties vvould not be effected by changes

in ambient temperature. The bridge was then balanced and the detector

was left at its highest sensitivity for time intervals up to two hours.

During this time there v/as no apparent drift in the balance point.
39

Thus Instrumentation drift vas also considered negligible during the

time of sample testing.

A final error that v/as present in the experiment was the assumption

that the coil imbalance due to changes in metal conductivity were linear.

Some error was introduced into measurement values by this assumption,

but is thought to be less than 0.1% lACS at the midpoint of the two

standards, i.e., 31.9% lACS and less at conductivities which approach

the value of the standards being used. Further measurements with newly

constructed coils and with the variable frequency capabilities of the

bridge are being completed to determine the exact error that is present

due to this assumption.

Due to the’ lack of recent calibration of the calibration standards

the conductivities of the test pieces should be understood in a relative

sense. The changes measured are accurately measured with respect to the

standards and are repeatable but should be understood only as an

indication of change and not in an absolute sense. However, on an absolute

scale, the measurements are expected to be good within a few tenths of one

lACS percent.

The use of conductivity as an indirect hardness measurement in

aluminum alloys has been a well-established and useful technique for

a considerable time (16,17). It is well known, however, that hardness

is a multiple valued function of conductivity. The results established

here confirm this for 2219. Indeed there is a different branch of the curve

for each stage in the processing of the material. Therefore, supplemental

hardness measurements are generally required. This, along with the

problems of precision and accuracy discussed above, complicates the use

of conductivity. Careful consideration must be given to part geometry,

heat treatment history, and condition of the sample microstructure.
At present, eddy current conductivity measurements should always be

considered in a relative, rather than an absolute sense^ A conservative

interpretation of Figure 54 would require that the conductivity of

2219-T87*^ should vary no more than 1% TAGS from that of a piece of

known good material from the same lot, with a definite degradation of

material properties evident for a variation of greater than 2% lACS.
41

V.. ELECTRON MICROSCOPY STUDIES

Electron microscopy studies were carried out to determine the

direct relationships between thermomechanical processing and microstructure. An additional advantage of this approach lies in the fact

that physical properties including hardness, yield strength and possibly

NDE responses can then be correlated to microstructure.

Direct determination of microstructural changes is especially

important in a complex material such as 2219 aluminum alloy where a

variety of process dependent, interrelated and often competing phase

transformations may occur. Indirect measurement methods such as hardness

or electrical conductivity are in general not capable of distinguishing

between the various often simultaneous changes in several phase components.

Thus, when solely based on such measurement, the capability of predicting

the influence of changing orocessina conditions on physical behavior is

at best limited.

Aluminum alloy 2219 as indicated earlier has a nominal concentration

of wt^Cu with other minor constituents (see Table I). The

precipitation characteristics of this alloy are dominated bv the presence

of Cu and are similar to those exhibited by the binary Al-6.3wt"Cu

alloy. The aluminum rich end of the Al-Cu phase diagram is shown in

Figure 55. At equilibrium the solid consists of a two phase mixture of

a-aluminum and the intermetal 1 ic compound, 0 -AI

2

CU. This equilibrium,

however, is not achieved at low temperatures or with rapid cooling

rates. Instead, copper rich G.P. zones, and the metastable 0" and 3'

phases that are indicated in Figure 55 may form. The outstanding mechanical

properties of Al-Cu alloys are based on the precipitation of a fine

dispersion of G.P. zones and the metastable phases. The final microstructural

state will depend on the thermomechanical processing history. Although
the behavior of the 2219 aluminum alloy is in its essentials similar to

the comparable Al-Cu binary alloy, the presence of the minor elemental

constituents has important consequences.

The influence on aging response of the various minor constituents

is complex. When in solution, the presence of Fe in Al-Cu binary alloys

is deleterious, both with respect to reducing the peak hardness achieved

on artificial aging and in reducing the aging rate (18). The elements Mn

and Si, on the other hand, have the opposite effect although in an alloy

containing 4.5wt%Cu, Mn was found to be deleterious (18). Age-hardening

at room temperature was not observed in an alloy containing 4wt%Cu and

0.5wt%Mn (19) while the comparable binary alloy without Mn exhibits

significant age-hardening. The element Zr has been shown to have an

effect on aging behavior which in many respects is similar to Mn (18).

The response to a given element addition can also be strongly influenced

by the aging treatment. Although an Al-4wt%Cu alloy with a 0.5wt"Mn

does not exhibit two stage .aging at 160°C, pre-aging at 120°C does lead

to this response (20). When the concentration of additional elements

exceeds the solubility limit, a negative effect on age hardenina is

often observed (18). This is associated with the formation of

copper containing compounds that themselves do not contribute to hardening

but reduce the relative concentration of available Cu in the matrix. In

general, a decrease in available Cu is accompanied by a significant

reduction in age-hardening. Several insoluble Cu bearing compounds are

found in 2219 aluminum alloy. However, these have little effect during

normal processing since excess copper is available at the solution

treatment temperature. Finally, it should be pointed out that the

elements Zn, V, Mn and Ti play an important role in achieving grain
43

refinement during casting and in controlling recrystallization and grain

growth during thermomechanical treatment (21 )•

This portion of the investigation was concerned mainly with evaluating

the effect of an abnormal quench from the solution treatment temperature

on the properties of a material given an otherwise normal T87* treatment.

The majority of the specimens subjected to electron microscopy examination

were taken after the quench step or after final aging. Some additional

specimens given a T851 treatment were examined. The T851 treatment

differs from T87* in that a stretch of 2-1/4% rather than 5% is employed

and final aging is carried out at 177°C for 18 hours instead of 172°C

for 16 hours. Specimens obtained from the 10 to 1 reduced cross-section

ingot in the as-cast state were also studied as described in a previous

section. The purpose here was to confirm, by means of electron diffraction,

the identification of interdendritic phases that had been examined

optically and in the SEM. It was also of interest to determine what, if

any, precipitates might exist within the primary dendrites to answer the

question concerning the origin of the numerous insoluble precipitates

found distributed throughout the material after processing. In studying

aged specimens, special consideration was given to correlating microstructural

observations with the C-curve behavior described in the previous section.

1 . Experimental Procedure

With the exception of the as-cast ingot all specimens were prepared

from rolled plate stock. Specifications describing the condition of the

starting materials and details of the methods emoloyed in the various

laboratory processing steps are given elsewhere in this report. Identification

of the specimens is by number. In discussing a particular specimen, the

number will be stated together with a brief descriotion which will serve

to identify that aspect of the processing sequence which was unique to
44

the specimen. For convenience, a complete list of specimens that were

examined in the TEM and those examined in the SEM that are discussed in

this section is given in Table X. The processing treatment for each

specimen is indicated. Additional information on these specimens is

given in Table VI.

To prepare a specimen for TEM examination, a thin section was cut

along a plane normal to the original rolling direction of the plate. In

the case of the as-cast ingot, the section was parallel to the solidification

direction. Except for a few samples prepared early in the investigation

in which spark machining was used, all sections were cut using a low

speed diamond saw. The thickness of these sections was approximately

0.2 mm. Disks 3 mm in diameter were punched from the sections and jet

electropolished in a solution consisting of 30% HNO^ and 70% methyl

alcohol by volume. The electropolishing solution was cooled to about

-60®C. In a few instances, to minimize the introduction of mechanical

damage in the very soft specimens that had been solution heat treated

but not stretched or aged, 1 mm thick sections were cut and electrochemically

thinned using the so called window method (22).

TEM studies were conducted with three instruments, a JEOL 200 A

operated at 200 kV, a JEOL lOOB and a JEOL lOOCX. In the latter two

instruments observations were carried out at 100 kV. The JEOL lOOCX, is

designed to function in either the conventional transmission mode or the

scanning transmission (STEM) mode which employs a highly focused electron

probe a few nm in diameter. The JEOL lOOCX was also equipped with an

energy dispersive x-ray analysis system supplied by the Kevex Corporation.

When applied to a suitably thin foil, it is possible with this system

utilizing the STEM mode of operation to obtain an elemental analysis of

a column of material through the thickness of the foil as small as 10 nm
in diameter. Analysis is applicable to elements having atomic numbers

higher than Ne. The results reported in this investigation were corrected

for background level and the relative elemental concentrations were

calculated by means of a program termed "Foil" that was supplied by the

manufacturer (Kevex). Despite these correction procedures, the results are

subject to considerable uncertainty. Accurate determination of elemental

composition can be complicated by a number of factors, especially when

the region of interest may be a small particle within a matrix having a

different composition. If a layer of matrix material overlays the

particle, then the contribution of the matrix must be taken into account.

Preparation of the foil specimen may alter the near surface composition

or leave a deposit differing in composition from the particle of interest.

If the specimen is not sufficiently thin, effects due to beam spreading,

absorption and fluorescence may be introduced. It is only with the

accumulation of a number of measurements together with other information

such as electron diffraction data that confidence can be gained in a

quantitative analysis. Despite the complications that exist in analyzing

small particles, even a qualitative analysis can provide information not

available by other means.

Some specimens subject to TEM study were also examined by means of

scanning electron microscopy. The SEM samples were mechanically polished

then electropol ished and lightly etched in Keller's solution. Large

3 and 3' precipitates produced during altered quench treatments were

readily observed by this method. Large particles remaining at the end

of the solution heat treatment were, of course, also visible. This

method has a considerable advantage in that large areas can be examined

ai relatively low magnifications, and a representative picture of precipita

concentration and distribution can be obtained. To achieve the same
46

result by means of TEM study would require the preparation and examination

of a large number of specimens. TEM and STEM are, in general, necessary

for the identification of precipitates, especially when they are less

than a micrometer in diameter. Precipitates responsible for age hardening

are not readily amenable to SEM study.

2. Results

The observations reported below were made on specimens derived from

rolled plate stock. The results are divided into subsections under the

following headings: Solution Heat Treated and Quenched Structure, Stretched

and Aged Structure, and Microstructure After Quench Treatment.

(a) Solution Heat Treated and Quenched Structure - In order to study the

as-solutionized structure, specimens taken from 3.81 cm thick plate in T851

condition (specimen #879--55) and from 0.635 cm thick plate in the T37* condition

were solution treated at 535®C for 75 minutes and quenched in ice water.

The microstructure of these two materials did not appear to

differ with the exception of the extensive recrystallization and grain

growth that occurred in the T87* material and not in T851 . The latter

effect is shown in Figures 56 and 57. Figure 55 shows the as-received

grain structure of 2219 aluminum alloy plates in the T87* and T851

conditions. There is no discernable difference between the two structures.

Figure 57(a) and 57(b)’ show the grain structures after solution heat

treatment and quench of the two plates. The anomalous grain growth in

the T87* plate is ascribed to the higher prior cold work (5?0 in this

plate versus 2 1/4% in the T851 plate. This observation was verified by

solution heat treatment of a 2219-F (as-fabricated) plate obtained from

the Reynolds McCook plant. Figure 57(c).

A TEM micrograph of the resolutionized T351 (specimen #879-25) is

shown. in Figure 53. Numerous particles are present ranging in size from
47

a few tens of nm to nearly a uni in diameter. There was considerable

variability both in the size and distribution of these particles. In

some regions, observed at the same magnification as Figure 58, no particles

were visible while at other locations numerous larger particles were

found. Some of the large particles are visible in SEM and optical

micrographs contained elsewhere in this report.

The TEM sample shown in Figure 58 was prepared specifically to avoid

mechanical damage and the attendant introduction of dislocations. The

dislocations visible in Figure 58, and in Figure 59 from the same sample,

are arranged in subboundaries and arrays. This is typical of materials

that have been deformed and subsequently annealed.

A number of particles were analyzed both by electron diffraction

and by energy dispersive x-ray analysis utilizing the STEM instrument.

A STEM micrograph of resol utionized T87* material (specimen #197) is shown in

Figure 60. X-ray spectra and electron diffraction patterns were obtained

from the labeled particles in Figure 60. The precipitate labeled Q is

shown at a higher magnification in Figure 61, together with its associated

x-ray spectrum and electron diffraction pattern. According to the

diffraction pattern, the crystal structure is appropriate to the Cu^FeAl^

phase, which has been identified previously in the interdendritic regions

of as-cast ingot specimens. The concentrations of A1 , Cu and Fe determined

from the x-ray spectrum are in approximate agreement with the composition

of the Cu2FeAlj phase. Note, however, that there is a small Mn peak

indicating that this element has partitioned to the particle. X-ray

analysis of particles L and E in Figure 60 also indicated that they were

probably the Cu^FeAU phase.

The precipitate at R in Figure 60 was not conclusively identified.

This precipitate is shown at a higher magnification in Figure 62 with its
x-ray spectrum. The relative concentrations of Al, Cu and Mn suggest

that R may be the phase Cu2Mn2Al2g. The small V peak in the spectrum

also indicates that significant partitioning of that element to the

article has occurred. The x-ray spectrum from the a-aluminum matrix is

shown in Figure 62 for reference. Only Al and Cu are indicated to be

present. Because of their low concentrations, the elements Fe, Mn and V

found in the above particles were not detected in the matrix. Other

elements, Ti, Zr and Si which according to chemical analysis are present

in the material were not detected in the matrix.

The above brief study of a few precipitates occuring in resol utioni zed

and quenched specimens was by no means exhaustive. It is quite likely

that further study would reveal the existence of other phases consistent

with the composition and solution heat treatment temperature of the 2219

aluminum alloy. In particular, none of the small particles examined in

Figure 60 were found to be 0-CuAl2.

Even though the above samples had been held at room temperature

('^20°C), for as long as several dajs in some cases, there was no evidence

of the formation of 6.P. zones.

(b) Stretched and Aged Structure - Deformation by stretching the asquenched material in tension leads to a high density of relatively

uniformly distributed dislocations. Figure 63 shows the dislocation

structure in a resol utioni zed and quenched T851 specimen after stretching

in tension by 2-1/4% (specimen #1). The accompanying diffraction pattern

in Figure 63 (after tilting to a [100] zone orientation) is characteristic

of the a-aluminum matrix structure. Reflections that might be

associated with the formation of G.P. zones, 0" or 0' precipitates are

not observed. Aging the above structure for 18 hours at 177®C to complete
49

the 1851 processing sequence produced the structure shown in Figure

64(a) (specimen #1A). The diffraction pattern included in Figure 63(a)

was taken along a [100] a-aluminum zone axis. The square array of large

spots are from the a-aluminum matrix. The pattern of small spots identifies

the closely spaced fine precipitates as 0‘ . The microstructure in the

as-received T851 plate specimen is shown in Figure 64(b) and is essentially

identical to- that of the reprocessed material. For comparison, the T87*

"structure" is shown in Figure 65 (specimen #142). Qualitatively, the

microstructures of the T851 and T87* orocessed specimens are similar,

despite the somewhat enhanced strength orooerties of T87*.

Although the diffraction patterns in Figures 64 and 65 indicate that

the principal precipitate phase present is 0', a close examination of

both the T87* and T851 materials reveals a concentration of much finer

precipitates having a similar morphology and orientation to 0'. These

fine precipitates are visible among the larger 0' precipitates in Figure

66(a) taken at a higher magnification than Figures 64 and 65. Their

small size, shape and orientation tentatively identifies them as 0".

The diffraction pattern corresponding to Figure 66(a) is shown in 66(b).

Each of the spots can be identified as originating from the a-aluminum

matrix or one of the three 0' variants. Any contribution the 3" precipitates

might make is overwhelmed by matrix and 0* reflections. However, by

carrying out the appropriate dark field experiment, it is possible to

demonstrate that the small precipitates in Figure 66(a) are in fact 0".

A schematic drawing of the diffraction pattern of Figure 66(b) is shown

in Figure 67 eliminating all spots except for those eminating from the

matrix and one variant each of 0* and 0 ". Reflections produced by

double diffraction are also excluded. Because of the close proximity of

0

' to 3" reflections in this and other orientations, 3" cannot be displayed
separately under dark field imaging. However, by comparing a dark field

image obtained from the overlapping (003)^,, and (002)^, reflections with

a dark field image obtained from the (101 )q, reflection which contains

only 0* , the presence of 9” can be deduced. This is illustrated in

Figure 68. Figure 68(a) was imaged with a (101 )q,, reflection and only

9* precipitates lying on horizontally oriented (020) matrix planes are

visible. Figure 68(b) was imaged with overlaoping (003)^,, and (002)^,

reflections, and here both the small 9" and larger 9' precipitates are

seen. Weak images from the 0* habit variant lying on (200) matrix

planes are also visible since the imaging conditions did not entirely

exclude the contribution of nearby reflections from that variant. The

dark field imaging conditions for Figures 68(a) and (b) are indicated in

Figure 67. The specimen from which the micrographs in Figures 66 and 68

were obtained was subjected to a quench interrupt at 400®C for 15s on

cooling from the solution heat treatment temperature at 535®C. Otherwise,

the specimen (#94) was processed according to T87* practice. Similar

observations of 0" precipitates were made in specimens processed according

to T851 , and T87* and after a number of altered (sequence A and B) quench

treatments, as will be described later.

Omitting the 2-1/4% stretch normally included in the T851 process

leads to the microstructure shown in Figure 69 (specimen #879-35).

Bands of 9' precipitates are present within a fine dispersion of much

smaller homogeneously distributed 9 " precipitates, rather than a predominanc

of uniformly distributed 9* precipitates seen in Figure 64 after normal

T851 processing. Although a similar specimen given the T87* process

without stretching was not examined in the TBi, a similar result would

be expected. The shorter aging time and slightly lower aging temperature

of the T87* process is not expected to lead to a substantial difference

in the precipitation behavior.
51

A higher magnification view of the microstructure in Figure 69 is

shown in Figure 70. It can be seen that a region free of 3" precipitates

surrounds the larger 0' precipitates. Positive identification of the Q"

precipitates is afforded by the diffraction pattern included in Figure

70. Only a-aluminum matrix reflections and 9“ reflections are present,

9' precipitates were not present in sufficient numbers to contribute to

the diffraction pattern. The short streaks located at {1 0 ^

}, {001}

and {1 0 I

} with respect to the a-aluminum lattice serve to identify the

precipitates as 0''(3).

The bands of 0' precipitates in Figure 69 can be associated with

the presence of dislocation arrays and subboundaries similar to those

shown in Figures 58 and 59 which exist after quenching from the solution

heat treatment step. The initial precipitation of 0' is known to occur

heterogeneously at dislocations. After quenching from solution heat

treatment, the majority of the dislocations are located in rather widely

separated arrays and subboundaries as shown in Figure 58. Deformation

by stretching increases the density and leads to a relatively uniform

distribution of dislocations throughout the structure (Figure 63). These

dislocations now act as sites for the nucleation of 0' precipitates during

aqinq. This process, of course, accounts for the high concentration of

a' precipitates in stretched materials.

(c) Microstructure After Quench Treatment - The microstructure of

selected specimens subjected to altered quench treatments (pre-aging treatments)

was studied after the pre-aging quench treatment step and, in many cases, after

completion of the T87* process. When the cooling rate from the solution treatment

temperature is sufficiently fast a supersaturated solid solution of

copper in aluminum is obtained. The only additional phases present at

the end of the quench are these that exist at the solution treatment
52

temperature. A slow rate of cooling, a pre-aging treatment, or other

thermal cycle prior to stretching and aging may result in the growth of

an existing phase or the precipitation of additional and new phases.

The microstructural studies described here were concerned with the

detection and identification of these changes. Specimens given a

“sequence A“ pre-aging treatment will be considered first followed by

those given a reheat cycle after initially quenching “sequence B“.

SEM micrographs of specimens given quench interrupts at 400®C for

15, 30 and 60s (specimens #93, 81 and 85) are shown in Figures 71(b),

(c) and (d), respectively. For reference. Figure 71(a) shows the asquenched structure (specimen #197) in the absence of any pre-aging. A

progressive increase in the concentration and size of visible precioitates

is evident in advancing from (a) to (d). Precipitates are present both

within grains and along grain boundaries, but the largest precipitates

appear to form along qrain boundaries. Grain boundaries are known to

act as preferential sites for the nucleation of the e-CuAl^ phase. When

the shapes of the precipitates could be sufficiently well resolved, as

in Figure 71(d) for example, it was clear that many precipitates had the

form of needles. The needle-like appearance may in fact be the result

of thin plates or disks viewed edge-on. Since the 0' phase has the

required lamellar shape and the pre-aging temperature is appropriate to

the formation of this phase, many of the precipitates seen in Figure 71

may be 0'. However, to be consistent with {001} habit exhibited by 0 ',

a pattern of alignment along three directions with an appropriate angular

relationship would be expected in each grain. That this was not the

case can be seen by closely examining Figure 71(d).

Observations after pre-aging treatments at 450^^0 were similar to

those at 400*^0. A specimen given a pre-aging at 450®C for 30s (specimen #69)
53

is shown in Figure 72. The distribution of precipitates is displayed at

a relatively low magnification in Figure 72(a) and at a higher magnification

in Figure 72(b). Consistent with the slightly poorer strength properties

that were measured after a pre-ag1ng at 400®C for 30s, the concentration

of precipitates in Figure 71(c) appears to be greater than in Figure 72(b).

In assessing precipitate concentrations with this method, it must be

cautioned that grain orientations and etching rate can have a considerable

effect on the observations.

A TEM micrograph of precipitates formed as a result of a pre-aging

treatment at 400°C for 60s (Figure 71(d)) is shown in Figure 73. A

second micrograph of the same specimen with dislocations in contrast is

shown in Figure 74. Misfit dislocations at many particle interfaces and

strain induced dislocations in the surrounding lattice are present. The

misfit dislocations are a result of the loss of coherency between precipitate

and matrix. Electron diffraction patterns obtained from various precipitates

indicated that most were either the 9 or 3' phase. A duplicate specimen

(#86) which was taken through the remainder of the T87* process is shown

in Figure 75. The large precipitates were produced during the pre-aging

treatment while the small a' precipitates dispersed throughout the

structure were formed during aging. Note the precipitate free zone

surrounding the large precipitates. There was little evidence of a"

precipitates in this specimen. The a" phase was readily observed after a pre-aging treatment at 40C®C for 15s as has been demonstrated in Figures

66 through 68.

Figure 76 is a dark field micrograph of a specimen given an interrupt

at 450°C for 60s (specimen #105). The two precipitates visible in bright

contrast were determined to be 9. A third, larger inclusion to which the

two 9 precipitates aopear to be joined was not identified. The larger

of the two 9 precipitates, in aodition to its junction with the unidentified
54

particle, is also associated with a matrix grain boundary.

Precipitates that are 0' are indicated in Figure 77.

This specimen (#6) had been given a pre-aging quench treatment at 350®C for 15s

The precipitates are thin plates parallel to {001} matrix planes as is

characteristic* of 0‘ . The presence of pre-existing particles from the

solution treatment step together with the small size and low concentration

complicates the identification of particles that may have formed during

the pre-aging period. Note that a second much smaller particle appears

in conjunction with each of the larger 0' particles.

SEM micrographs of specimens given a sequence B quench treatment

are shown in Figure 78. It may be recalled that in this treatment the

specimen is quenched into ice water from the solution treatment temperature,

isothermally annealed, and then quenched again into ice water. Analogous

to sequence A behavior the precipitate size and visible concentration

increased with longer pre-aging times. Grain boundaries were also

decorated with precipitates’ as was observed for sequence A treatments.

The Widmanstatten pattern of precipitates formed after an anneal at

400®C for 30s (specimen #232, Figure 78(c)) provides a strong clue to

their likely identity as 0'. This was confirmed by electron diffraction.

A TEM micrograph of this specimen is shown in Figure 79, displaying the

morphology and orientation appropriate to the ©' phase. The identity of

precipitates formed at 450°C has not been confirmed by TEM studies.

A feature that seemed to be characteristic of sequence B specimens

and not of sequence A specimens was the appearance of a vein-like pattern

of precipitates. This is evident in Figures 78(a) and (c), and, although

not shown, was also seen in the specimen of Figure 78(b). The presence

of these veins of precipitates is reminiscent of the bands of 0 precipitates

observed in specimens aged without stretching. Figure 69. In that case.
55

it was concluded that the bands were a result of heterogeneous nucleation

of 9 ‘ at subboundaries. A similar explanation may be advanced here. It

was also noted that veining was much less evident in large recrystallized

grains.

The hardnesses of specimens shown in Figures 71, 72 and 78 are listed

in Table XI. The hardness measurements were taken after completing the

T87* process and reflect the influence of the altered quench treatment.

Comparing sequence A and B specimens it appears that for the same hardness

a higher precipitate concentration occurs in sequence B specimens. For

example, compare Figure 71(c) to Figure 78(c) both with a hardness of

^7HRB and Figure 72(b) to Figure 78(a) having a hardness of '\^72HRB. It

is also interesting to note that the hardness of specimens pre-aged at

400°C decreases with time at about the same rate in sequence A and B

while at 450®C the change is more rapid in sequence B. On the basis of

these observations it is apparent that the precipitation process and its

effect on properties differs for the two quench treatments.

Utilizing the STEM instrument x-ray analyses were carried out on a

number of the precipitates observed in sequence B specimens. Figure 80

is a TEM micrograph from specimen #249 reheated to 450®C and held 15s.

Precipitates labeled A, B, and C were found to consist of A1 and Cu and

are probably 9 or 3' . The indicated A1 concentration was higher than

the stoichiometric value of 45.9wt^U probably because the particles were

embedded in the a-Al matrix. For example, the indicated A1 concentration

in precipitate B was 34wt^. The x-ray spectrum of B is shown in Figure

81 (a). The same spectrum is shown in Figure 81 (b) on an expanded vertical

scale to demonstrate the presence of a small Mn peaks at about 5.9 kev. A

very small Mn peak could also be detected in spectra from orecioitates 3 and C.

In general, Mn appears to partition to the 3 and/or 3' precipitates.
56

The spectrum of precipitate Z is shown in Figure 81(c), In this

case, in addition to Cu and A1 there is a small Zr peak. Close examination

of Z in Figure 79 suggests that there are two rather than one precipitate

present. Thus, the spectrum in Figure 81(c) may be a composite obtained

from two precipitates. Other precipitates examined in this specimen

were found to contain Cu and Fe in addition to A1 and were probably the

Cu

2FeAly phase which remained after solution heat treatment.

3. Discussion

Although this investigation did not embrace a complete study of the

precipitation behavior of 2219 aluminum alloy, the observations, as

expected, indicate that its behavior is similar to the binary Al-6.3wt%Cu

alloy. The age hardening response of Al-Cu alloys has been studied in

detail by Hardy (23) and the precipitate species determining this response

have been identified by Silcock, Heal and Hardy (24). Details, as they

are presently understood, of the nucleation and growth mechanisms of the

four species, G.P. zones, 0", 0' and o-CuAl^, that occur in A1 rich AlCu alloys have been summarized by Lorimer (25). In an extensive investigation

employing electron microscopy, Hornbogen (26) has analyzed the precipitation

processes and determined the nucleation diagrams for a series of Al-Cu

alloys ranging up to 6 wt%Cu. The nucleation diagrams constructed by

Hornbogen provide a useful means of describing the aging behavior of AlCu alloys. Two of these diagrams, one for 5wt?Xu and the other for

1.95wt%Cu are reproduced in Figures 82(a) and (b) respectively. The Al5wt%Cu alloy is essentially a close binary counterpart of the 2219

aluminum alloy which, at the solution heat treatment temperature of

535°C, contains approximately 5wt%Cu in solid solution. By employing

the nucleation diagram in Figure 82(a), the aging behavior of 2219

aluminum alloy, insofar as it is similar to the binary alloy, can be

described as follows.
57

On cooling to a temperature between 520 and 400®C and holding, the

equilibrium phase e-CuAl^ nucleates heterogeneously at grain boundaries

and grows. Below 480®C not only is 0 formed at grain boundaries but the

metastable phase a' appears. This precipitate also nucleates heterogeneously,

however, the preferred sites in this case are dislocations. If the

specimen is held for a sufficiently long period of time, the 9' precipitates

transform to a. At temperatures approaching 200®C, however, the transformation

e‘-»6 becomes very slow. It is clear from this diagram and the fact that

9 nucleates only at grain boundaries and existing a' precipitates, that

9' will be the first precipitate to form within grains. Because a'

itself nucleates heterogeneously at dislocations, the presence of dislocations

will have a profound effect on the initial concentration and distribution

of both a' and a precipitates. The temperature range of the nucleation

diagram just described, 210®C to 480®C, corresponds to the region that

was explored in the sequence A and B quench treatments. t

At tempera tues below 210°C formation of metastable 0“ is indicated.

Although not shown in Figure 82(a), it is generally believed that G.P.

zones precede and are a prerequisite for the formation of a" precipitates

(25), that is, the sequence G.P. Zones -* a" is required. G.P. zones form

homogeneously throughout the matrix so a" will also appear to be distributed

homogeneously. Although some controversy may exist (25,27) it is generally believed

that the reaction a" - a' does not occur. Therefore, the curve V_ in

Figure 82(a) is not valid. The continued formation of a' which initially

nucleates at dislocations is thought to be autocatalytic. Since a' is

the more stable phase, it grows at the expense of nearby a" precipitates

which dissolve to support this growth.
58

The effect on microstructure of the preaging stretch in the T851

and T87* processes can now be explained. Without the stretch, it was

demonstrated that the majority of the dislocations present in as-quenched

specimens were at subboundaries. Thus, on aging the predominant precipitate

phase was 0” with 0' in bands at subboundaries. Although the experiment

was not carried out, it is expected that continued aging would have

caused the width of the 0' bands to increase expanding into regions occupied

by 0". Stretched specimens contain a high dislocation density and a

correspondingly high concentration of sites for the nucleation of 0 ' ,

consequently the major precipitate phase is 0 '. Local regions that

happen to be free of dislocations are occupied by 0". This accounts for

the clusters of 0" precipitates that were observed in some stretched and

aged specimens.

An attempt will now be made to rationalize the microstructure of

2219 aluminum alloy specimens exposed to sequence A and B quench treatments

with the binary nucleation diagrams. A summary of the precipitate

species observed in sequence A and B specimens before stretching and

aging is as follows: (1) Both quench treatments resulted in a significant

increase in the amount of 0 at grain boundaries, (2) At 450®C, with

increasing time, sequence A specimens exhibited initially 0 and then 0

'

precipitates within grains, (3) A similar observation was made at 400®C

except 0

' was observed earlier in the process and may have preceded the

appearance of 0 within grains, (4) All specimens given a sequence 3

treatment at 400®C and 450®C exhibited a predominance of 0

' often arranged

in a vein-like pattern.

The formation of 0 at grain boundaries is in good agreement with

binary behavior. On the other hand, the early appearance in sequence A

specimens at 450'’C of significant amounts of Q in the interior of grains

in the absence of 0

' is not predicted by the binary nucleation diagram.
59

However, on examination of specimens quenched into ice water from solution

heat treatment, it was established that 2219 aluminum alloy contains a

significant concentration of insoluble precipitates. Boundaries at

these precipitates as well as a-Al matrix grain boundaries can act as

.sites for the nucleation of 9 . Indeed, 9 phase was sometimes noted at

such precipitate boundaries. The observation of 9 ' at 400®C earlier than

at 450®C indicates an increase in nucleation rate at lower temperatures

and is consistent with the binary alloy behavior. This tendency for 9

'

to nucleate readily at low temperatures may also explain the significantly

higher concentration of that phase in sequence B specimens than in

sequence A specimens. Tne cycle to ice water and reheating that was not

experienced by sequence A specimens resulted in the relatively profuse

nucleation of 9' which subsequently grew at the reheat temperature. The

observation of veins can be accounted for by the presence of subboundaries

at which 9

' has precipitated. It is not clear why similar veins were

not observed in sequence A specimens when 9' precipitates were detected.

The primary effect of the large e and 9' precipitates formed

during sequence A and 3 quench treatments is the removal of available Cu

atoms from the matrix. As a result, after aging, regions exist surrounding each

of these relatively large precipitates that are free of the fine precipitates

which are responsible for age-hardening. When extensive growth of 0 and

9' phases occurred during long interrupt or reheat periods, the concentration

of Cu in the matrix was found to be so reduced that 9 " precipitates were

no longer observed after a T87* treatment. As seen in the phase diagram

of Figure 55, the available Cu concentration throughout the matrix can

be reduced to a point where the aging temperature (172°C) lies above the

9

" solidus. Under these circumstances the nucleation diagram shown in

Figure 32(a) for 5wt"Cu is no longer applicable at any
60

point in the matrix and diagrams at lower Cu concentrations must be

used. For example. Figure 82(b) shows the diagram at 1.95wt%Cu. The

aging temperature of 172°C is now above the nucleation curve for Q“ and

that phase no longer forms. Furthermore, the nucleation curve for 9' is

displaced to the right and the formation of 9

‘ is retarded in comparison

with the 5wt%Cu.

Having considered the effect of altered quench treatments on

microstructure, the relationship between microstructure and physical

properties will now be examined. In comparison with properly quenched

material, the hardness of specimens exposed to sequence A and B quench

treatments was lower both before and after stretching and aging. The

reduced hardness before stretching and aging can be attributed to a

diminished solid solution hardening contribution associated with the

loss of Cu atoms from the matrix. The large 0 and 0' precipitates which

are responsible for this loss, contribute little to hardness. Similarly,

the reduced matrix Cu concentration also leads to a higher electrical

conductivity. After stretching and aging, hardness is determined mainly

by the concentration of 0' and 0" precipitates. The concentration of 3'

and 0" precipitates is, in turn, determined by the amount of Cu in

solution.

The C curves, whether determined before stretching and aging or

after the completion of the T87* process, can be related to the concentration

of Cu in solid solution. The C-curves may, therefore, be regarded as

nucleation curves (or more properly as the time-temperature- transformation

curves) for the formation of o and 0'. In the temperature range considered,

the C curves do not distinguish between 3 and 3 '. Formation of the two

phases overlaps and, moreover, with sufficient time 3' transforms to 3.

The C curves are not a simple function of time and temperature but

depend both on path and on the initial microstructural state of the

material. Thus, the same C curves are not obtained for sequence A and 5
61

quench treatments. These differences were also reflected in the different

microstructures that resulted from the two treatments.
62

VI.. HEAT FLOW-PROPERTY PREDICTIONS

A heat flow model is developed and used here to calculate almost all

conceivable heat flow conditions anticipated during the quench of 2219

aluminum alloy plates from the solutionizing temperature of 535®C. The

calculated time- temperature. data is then coupled to the C curves established

in the previous section. The variations in properties across different

thickness plates for the worst and the best heat flow conditions are

thus predicted.

1 . Heat Flow Model

The heat flow calculations were carried out for the cooling of a

flat plate from an initial temperature of T^. The differential equation and

the boundary conditions for the temperature distribution in the plate,

-

T(x,t), are

(3T/at) = «(32T/3 x2),

T(x,0) = Tq - 0 1 X <_ L,

k(3T/3x) - hi(T-T^) =0 X = 0,

k(3T/3x) + h2 (T-T^) = 0 . L,

( 11 )

( 12 )

where x is the spatial variable, L is plate thickness, t is the time, a is the

thermal diffusivity, T^ and T^ are the initial and final temperatures of the

plate, respectively, k is the thermal conductivity, and h.j and h

2 are the heat

transfer coefficients at the top and bottom surfaces of the plate,

respectively. In terms of the dimensionless variables, ri = x/L, q

=

(T-T^)/(T^-T^) , Fo = ctt/L^, Bi.| = h.jL/k, and Bi

2

= h

2 L/k, the above

equations are:
63

(30/3Fo) = 3-0/3n^

0(n»O) * 1 0 1 n ^ 1

39/3ri " Bi^0 ~ 0 n * 0

30/3n + Bi20 * 0 n = 1

UsinQ results of Cerslaw and Jaegsr for constant heat transfer coefficients

(28 ), we find:

0(n,Fo) = 2|^l^C^{(x^/Bii)cosx^n + sinx^n>exp(-Fox2 )

,

with

Cn * tC(x„/Bii)sinx^ - cosx^ + I]d2>/U^[did2 + (di/Bi2) + (da/Bii)]}

j di - 1 + (X^/Bii)2

d2 = 1 + (X^/Bi2)2

2

X^'s are the positive roots of [x - Bi-jBi 2

]sinx - (Bi^ + Bi

2

)xcosx = 0

with

The thermophysical properties used in the calculations that follow

were:

Initial temperature = 535®C

Water temperature = 40®C

Thermal Conductivity k = 1.2W/cm.K

2

Thermal Diffusivity a = 0.5 cm /s

Heat Transfer Coefficient* h = 0.8 W/cm^K

2. Heat Flow Calculations and Property Predictions

The heat flow calculations were carried out using the computer code

MOLlQ (29). These included the following:

(a) Symmetric cooling of the plate from both top and bottom surfaces

2 under normal experimental conditions, ^^2 ~ .K.

*This heat transfer coefficient was deduced from simultation of temperature

time data on the computer and comparison of same with actual data obtained

in laboratory and commercial practice. This value approximates the normal

condition during water quench from the solutionizing temperature.
64

(b) Asymmetric cooling of plates, where heat is withdrawn from

only the top surface, h^ = 0 for all times.

(c) Symmetric cooling of plates from both top and bottom followed

by an abrupt variation in the heat transfer coefficient on the bottom

surface of the plate, h^ = 0, at different dimensionless times.

Time-temperature data from the computer program was then combined

with equations (4) to (6) for the determination of C curves using

the values of the constants reported in Table VIII. The numerical

procedure for the determination of a given property, e.g., yield strength,

was as follows. Equation (5) is integrated, using the calculated timetemperature data and equation (6) for a given position in the plate, and

the quality is determined. Using the values of and cJq from

Table VIII, the value of a, in this case yield strength, is established.

These computations are carried out numerically and simultaneously with

the heat flow calculations.

Finally, for a given sequence (A or B) of heat treatment, the values

of the constants K^, and are identical for all properties in question,

while a^, and differ according to Table VIII. Under these conditions, i

follows from equations (4) to (6) that the quantity !<2 ln[(a-aQ)/(aj^-aQ)]

remains the same for all properties, e.g., hardness, tensile strength, and

conductivity, for a given sequence. Thus, from the yield strength results

one can readily obtain all the other properties without further heat

flow calculations.

(a) Symmetric Cooling

Results for the symmetric heat flow from both sides of a plate

using dimensionless variables Bi^ = Bi

2

= Bi = hL/k = 5.0, and 0.5

are shown in Figures 83 and 84. Using the thermophysical properties

listed above the following relationships between the Biot number and

plate thickness, and Fourier number and time are deduced:
65

B1 - 0.67L and t = 2(Fo) (17)

For example, equation (17) and Figures 83 and 84 show that the

centers of 7.5 cm and 0.75 cm thick plates would reach a temperature

of 200®C from an initial temperature of 535 ®C in '^Zl seconds and

M.2 seconds, respectively.

Figure 85 shows the actual calculated time-temperature data at

four locations in a 15.24 cm (6") thick plate.

(b) Asymmetric Cooling

In these calculations it was assumed that heat was withdrawn

from only the top surface of the plate. The time-temperature

profiles developed are of course equally valid for plates with twice

the thickness subjected to symmetric cooling from both surfaces.

The data generated was 86 coupled to equations (4) to (6) as

described above to permit determination of yield strength in the

plates. Figure shows calculated minimum yield strengths in

the plates versus plate thickness for constants from Table VIII for

both sequences of heat treatments. The data are more representative

of sequence A heat treatment in that a continuous decrease in

temperature was calculated for all the cases. The minimum yield

strength for each plate thickness represents the bottom surface which

was assumed to be insulated. On the other hand, it could also represent

the centerline of a plate with twice the thickness which is cooled

from both sides. For example, the curve for sequence A in Figure 86

shows that the insulated bottom of a 12.7 cm (5 inch) thick plate

would have a yield strength of 45.9 ksi which is only lower than

the minimum Federal Specification QQA-250/30 requires. On the other

hand, the same curve also predicts a yield strength of 51.3 ksi "for the

same plate cooled symmetrical ly from both sides. The latter value
66

exceeds the minimum specification of 49 ksi for 12.7 cm (5 inch) thick

2219 aluminum alloy plates.

(c) Abrupt Variations in Rate of Heat Extraction From the Bottom Surface

The time-temperature data generated were for cases in which a

plate was subjected to symmetric cooling for a certain length of

dimensionless time, Fo=xt followed by abrupt insulation of the bottom

surface. It was assumed that this would represent an extreme case

of formation of an air gap or steam pocket in commercial practice.

Figure 87 shows the calculated time-temperature profiles for

a 12.7 cm thick plate cooled symmetrically for 6.45 seconds (Fo=t=0.02),

followed by an abrupt change in the heat transfer coefficient h

2

from

2

0.8 W/cm K to 0. The data shows significant recalescence in temperature

at locations near the bottom surface. This reheating phenomenon can

then lead to deterioration of properties if it results in additive

times that intersect the C curves for the alloy.

Calculated hardness and yield strengths for this 12.7 cm thick

plate for a variety of t values are shown in Figures 88 to 90. The

value of T=«> is equivalent to complete symmetrical cooling, while

T-0 depicts conditions under which the bottom surface is insulated

for all times. Figures 88 and 89 show the predicted hardness and

yield strength values using the C curves and constants developed

earlier for sequence A. It is interesting to note that the lowest

predicted properties are for t=0.02 (6.45 seconds). Trial and

error showed that these should represent about the worst conditions.

For example, these correspond to minimum values of hardness and yield

strength of 59. T HRB and 42.6 ksi, respectively at X/L = 0.9

(-^ll.A cm from the top surface). This represents a maximum deterioration

in yield strength of 13% below specification. ' If sequence B values

are employed the minimum predicted yield strength at the same location

* This T is not to be confused with x used in a previous section.
67

is 39 ksi. The latter probably represents the worst possible case

under the assumptions of these calculations.

Time-temperature profiles for a 7.62 cm thick plate at a

location 6.67 cm from the top surface for a variety of heat flow

conditions are shown in Figure 91. The calculated minimum yield strengths

for sequences A and B are shown in Figures 92 and 93, respectively. It

is interesting to note that the lowest predicted yield strength from

Figure 93 is ^5.3 ksi which is only ^^% lower than that specified in

Federal Specification QQ-A-250/30.

Predicted data for a 15.24 cm (6 inch) thick plate are shown

in Figures 44 to 96. As anticipated the deterioration in yield

strength is most severe for sequence B.

3. Summary of "Worst” Property Predictions

Similar calculations as shown above were carried out for all plate

thicknesses of up to 15.24 cm (6 inches). The data for the worst properties

(lowest yield strength, tensile strength and hardness; and highest conductivity

%IACS) were established using the computer model and trial and error methodology

described above. The data generated are shown in Figures 97 through 100.

Figure 92 shows the predicted minimum hardness in different thickness plates

when the "worst possible" heat flow conditions prevailed. For example, under

the "worst" conditions a 15.24 cm (6 inch) thick plate should show a minimum

hardness of ^^55 HRB somewhere close to (X/L = 0.9) its bottom surface. Figure

97 shows similar data for maximum predicted conductivities.

The predictive "worst possible case" yield and ultimate tensile strength

data are shown in Figures 99 and 100. Figure 99 also shows the minimum yield

strengths noted in Federal Specification QQ-A-250/30. These predictions show
68

that under the "worst" heat flow conditions, sequence B in Figure 99, plates

thinner than cm should meet the specifications. On the other hand, a

15,24 cm (6 inch) thick plate could have locations with yield strength of

ksi .

.
69

VII. ROUND ROBIN RESULTS

Round robin measurements of eddy current conductivity and Rockwell B

hardness were conducted by five laboratories on thirty samples of 2219-T87*

aluminum alloy. Each laboratory made six Rockwell B hardness measurements

and three eddy current conductivity measurements on each sample. Yield

and tensile strengths of each sample were measured by NBS. Thus, the results

obtained are pertinent only to the interlaboratory precision of conductivity

and hardness measurements and not to yield and tensile strength measurements.

Details and results are described herein.

1 . Samples

The samples were fabricated from the same 0.635 cm (1/4 inch) thick plate

of 2219-T87* aluminum alloy used for the work described in Section IV. Three

samples from this plate were chemically analyzed with the results shown in

Table V. The plate was cut into bars 2.54 cm (1 inch) wide by 18 cm (7 inches)

long with the long axis parallel to the rolling direction. The samples were

given thermomechanical processing in groups of four as described in section IV. 1.

Following the final aging treatment, one bar from each set of four bars

was machined into the space shown in Figure 101. Two of the bars from each set

were machined into tensile test specimens and the yield strength (0.2% offset)

and ultimate tensile strength were determined on a calibrated Satec System Inc.

Baldwin Model 60 CG Universal Testing System*. The two determinations were

averaged and these averages are reported here as the yield strengths and tensile

strengths of the round robin samples. In no case did the two values for yield

and tensile strength determined for each sample set differ by more than one

percent.
70

In all, thirty samples were circulated in the round robin. These included

two exceptions to the sequence A or sequence B thermomechanical treatments

described in Section IV. Sample number 276 received no stretch, and sample

number 5 received only a 2-1/2% stretch. All five laboratories readily

determined that the zero stretch sample did not fit property in a plot of

hardness versus conductivity. The results from this sample will generally be

excluded in the analysis below. However, the 2-1/2% stretch sample could not

be distinguished in this manner. For four samples, numbers 34, 38, 323, and

324, no yield or tensile strength data were available.

2 . Equipment

A total of five laboratories participated in the round robin. The

following equipments were used in the measurements by these laboratories:

1. A conductivity bridge constructed at NBS with an 1.3 cm diameter

probe operated at 15 kHz. The bridge was calibrated using two

Boeing conductivity standards of 28.81 ± 0.28% lACS and 35.07 ± 0.35%

lACS. The temperature of the standards and the round robin samples

was 23 ± 0.2°C. Hardness measurements were made on a Wilson bei'ich

model Rockwell hardness tester. The tester was checked and gave

correct readings on three Wilson tost blocks with Rockwell B

hardnesses 81.0, 59.7 and 39.0.

2. A Nortec NOT 5A Conductivity meter operated at 60 kHz. Two Boeing

standards, 29.3 and 41.6% lACS, were used for calibration.. The

calibration was checked against a third Boeing standard of 35.5%

lACS. Both the test specimens and the conductivity standards were

maintained at the same temperature (approximately 23'’C) during

measurement. Hardness was measured on a Wilson bench modern

hardness tester.
cn

71

3, A model NDT-5A Nortec conductivity meter with an 0.95 cm (0.375 inch)

model 3049C probe operated at 150 kHz. Calibration was with Boeing

standards. Measurements were made at 22 ± 2®C. Hardness was measured

using a Wilson Rockwell Hardness Tester Model 3-0R-7. The hardness

tester was checked using a Wilson Rockwell B test block with a hardness

of 69.4.

4. A Nortec N0T-5A conductivity meter with an 1.3 cn (0.5 inch) diameter

type 3049D probe operated at 60 kHz. Calibration of the meter was

made using aluminum standaro blocks with conductivities 29.8 to 42.8%

lACS at 23.9°C. A CCO Industries Rockwell B' tester with digital

readout. The hardness tester was checked using a calibration block

with a Rockwell [>• hardness of 79.1.

A magnotest FM-120 conductivity meter with an 1.3 cm (0.5 in)

diameter model 709 probe operated at 60 kHz. Two blocks with

conductivities of 42.0% lACS and 29.0% lACS were used as refi^rences.

The reference blocks and test samples were placed together on a

large aluminum block for 30 minutes prior to measurement to insure

temperature equality. Hardness was measured on a Model MC-4, Kentral

Hard'iess Tester calibrated using a Wilson Test block with a Rockwell

B hardness of 34.0.

3. Resul ts

Each of the five laboratories made six hardness measurcmeiits and three

conductivity measurements on each of the thirty samples. These measurements,

along with the yield strength, tensile strengths,

listed in Table XII.

and heat treatments, are
72

Table XIII gives the average of all hardness and conductivity measurements,

along with the respective standard deviations. The maximum observed single

sample standard deviations are 2.4 MRB for the hardness measurements, and 0.57

%IACS for the conductivity measurements. The average of the observed standard

deviations for all samples is 1.15 HRB for hardness and 0.30% lACS for conductivity

Figure 102 is a plot of hardness vs. ..conductivity for the thirty samples as obtained by the five laboratories. Each point on this plot represents the average

of the six hardness measurements vs. the average of the three conductivity

measurements made on one sample by one laboratory. The group of five measurements

which appear below the main sequence are from sample No. 276. This sample is the

one that received no stretching during the thermomechanical processing of the

alloy. Figure 103 shows the same relationship using the average hardness and

conductivity computed using all the measurements by all five laboratories on

each sample. The results in Figure 103 have been least squares fitted to the

quadratic equation

where H is the Rockwell B hardness and c is the conductivity in % lACS. The

values for aQ, a^ and a2 found are -652.95, 47.04, and -0.7521, respectively.

The residual standard deviation was 0.93 HRB.

Figure 104 shows the yield strength (at 0.2% offset) plotted as a function

of the conductivity determined by averaging the results obtained for each

sample by the five laboratories. The results have been least squares fitted

to the quadratic equation

H = aQ + a.jC +

2

(17)

2 (IS)
73

where Y is- the yield strength. The values obtained for 5

q, , and b^ are

-158.97, 15.76 and -0.2806, respectively, with a residual standard deviation of

1 .3 ksi

By least squares fitting, the yield strength vs. the conductivity measured

by each individual lab, the five curves displayed in Figure 105 are obtained.

Each data set was fitted to Equation (18). The parameters obtained are listed

in Table XIV.

Figure 106 shows the yield strength (at 0 . 2% offset) as a function of the

average hardness determined by averaging the results obtained for each sample

by the five laboratories. The results have been least squares fitted to the

quadratic equation

respectively. The residual standard deviation for this fit was 1.2 ksi.

By least squares fitting, the yield strength vs. the hardness measured by

each individual lab, the five curves displayed in Figure 107 are obtained. Each

data set was fitted to Equation (19). The parameters obtained are listed in

Table XV.

4. Discussion

The results of this round robin show that, for the range of conductivities

from 33 to 27 % lACS, an inter-laboratory agreement of about ± 0.6% lACS (at the

two sigma level) can currently be expected. For the single lot of 2219-T87*

aluminum alloy measured here, a conductivity measurement by any of the five

laboratories would predict the yield strength to about ±2.6 ksi and a hardness

(19)

The values obtained for c^, c-j , and C2 were 27.98, -0.1350, and 0.005906

measurement (using a boncii type hardness ) could predict t yield
74

strength to about ± 2.4 ksi (two sigma levels). Thus, for a single lot of

material^ conductivity provides almost as good a screening test as do bench

hardness measurements. It is believed that the interlaboratory agreement in

the conductivity measurement could be further improved if all laboratories

used conductivity standards certified by a single laboratory.

The large lot to lot variations in yield strength vs. conductivity

(see Figure 54) cannot be explained as errors in the measurement of

conductivity. The relative role of different processing variables in

these lot to lot variations is not presently clear. It should be re-emphasized

that, when NDT measurements are being made on a sample of 2219-TS7* from an

unknown lot, eddy current conductivity measurements alone are not sufficient

to screen for mechanical properties. Hardness measurements, or better yet,

yield strength measurements, must be made somewhere on the sample. Once this

is done, the remainder of the material can be screened using appropriate eddy

current measurements.
75

VIII. CONCLUSIONS

1 . As-received Plate

1.1 Moderate variations in composition, hardness, electrical conductivity and

mechanical properties were noted across the thickness of a 12.7 cm (5 inch)

thick 2219-T851 aluminum alloy plate. Composition variations, which influence

measured conductivities, can be traced to the original ingot. The variations

in hardness and tensile properties are mainly due to changes in cooling rate

across the plate during the quench and are probably influenced to some extent

by inhomogeneous mechanical deformation during processing.

2. Solidification Segregation Studies

2.1 Macrosegregation of copper in Direct Chill (DC) cast ingots of 2219 aluminum

alloy cannot be completely eliminated by chill face scalping and subsequent

thermomechanical treatment. Macrosegregation does remain in the finished

plate product. However, good scalping practice should limit copper content

to above the solid solubility limit with no deterioration in mechanical

properties.

2.2 Elements with equilibrium partition coefficients less than unity exhibit

macrosegregation similar to copper while those with coefficients greater

than unity are opposite to copper. The magnitude of deviations from the

nominal are related to the deviation of the coefficient from unity.

2.3 The major phases present in cast 2219 aluminum alloy in this study have

been determined by electron microprobe analysis and electron diffraction.

They are a-aluminum solid solution, a-CuAl

2

and Cu

2 FeAly. These phases are

also present in the heat treated finished plate product.
76

2.4 Predictable macrosegregation has been obtained in laboratory ingots of 2219

aluminum alloy. Both positive and negative segregation similar to DC cast

ingots are observed and are caused by the flow of segregated interdendritic

liquid.

2.5 Electrical conductivity determined by eddy current measurements of cast

2219 aluminum alloy is inversely related to copper content. This fact

complicates the relationship of conductivity to mechanical properties

used for nondestructive evaluation of the finished plate product.

2.6 Because of large copper content variation near the chill face,

surface hardness and eddy current measurements may be very sensitive to

scalping depth in their ability to evaluate the condition of finished

alloy plate.

2.7 Hardness, yield strength and ultimate tensile strength of heat treated

2219 aluminum alloy decrease significantly when the average copper content

drops below approximately 5.5 wt%.

3. C-curve Determination and Relationship Between Mechanical Properties

and Conductivity

3.1 No significant difference in either strength or hardness was detected

between alloys stretched between 5 and 7% permanent strain during the

thermomechanical processing of 2219 aluminum alloy.

3.2 The functional- form developed by Cahn and used previously by Staley for

7075-T6 and 6061 -T6 aluminum alloy was found to give an adequate

representation of the C curves for 2219-T87* if the form was modified to

include a minimum value for each property in question. Some deficiency

in this form at the highest and lowest temperatures was noted.
77

3.3 An efficient computer program was developed for using time- temperature and

property measurement data to establish C curve parameters.

3.4 Time temperature precipitation curves (C curves) were determined for hardness,

yield strength, tensile strength and electrical conductivity. The C

curves can be used to determine the correlations between these properties.

C curves could not be developed for elongation, probably because this

property is more sensitive to grain size and other factors.

3.5 A small but significant difference was found between the C curves for

sequence A (direct transfer to salt bath) and sequence B (water quench and

reheat in salt bath) type quenches. For a given salt bath time and

temperature, sequence 3 quenches resulted in a greater degradation of

mechanical properties.

3.6 The scatter in hardness and conductivity was found to be large. This

scatter can be expected to complicate NDE measurements and should be

properly taken into account when establishing NDE procedures and

specifications.

3.7 Because the "nose" of the C curves for 2219 is at a relatively high

temperature, 2219 aluminum alloy is not as sensitive to the types of

abnormal quenches studies here as some of the other high strength

aluminum alloys such as 7050.

4. Electron Microscopy Studies

4.1 The age-hardening response of 2219-T87* and T851 is determined principally

by the formation of O' precipitates with some contribution by' 3"

precipitates.

I
78

4.2 An abnormal quench treatment which results in dwell times significant with

respect to the C curves leads to heterogeneous nucleation and rapid

growth of 0 and 0 ' precipitates.

4.3 The nucleation and growth behavior of the 0 and 0‘ precipitates formed

during an abnormal quench depends on the pre-existing microstructural state

of the material and on the thermal "path".

4.4 The large incoherent 0 and 0 ' precipitates formed during an abnormal quench

consume copper available from the matrix and thereby reduce the concentration

of 0‘ and 0 “ precipitates that contribute to precipitation hardening during

subsequent aging.

4.5 The C curves are a. measure of the concentration of large 0 and 0

'

precipitates formed during the quench treatment.

5. Heat Flow Calculations - Property Predictions

5.1 Calculated plate properties, e.g., yield strength and hardness, decrease

monotonically with increasing distance from surface to centerline of a

plate for fixed heat transfer conditions.

5.2 For symmetric cooling and (sequence A) C curves, the calculated minimum

yield strength (at the center of the plate) is 54.9, 53.7, and 51.8 ksi

for 2.54, 7.62, and 12.7 cm (1, 3, and 5 inch) thick plates, respectively.

5.3 For asymmetric cooling and (sequence A) C curves, the calculated minimum

yield strength (at the bottom surface of the plate) is 54.4, 50.7, 45.9 ksi

for 2.54, 7.62, 12.7 cm (1, 3, and 5 inch) thick plates, respectively.

5.4 For plate thicknesses greater than 2.54 cm, (sequence B) C curves yield

lower properties values than (sequence A) C curves. For example, for

asymmetric cooling and (sequence B) C curves the calculated minimum yield

strength is 54.6, 48.0, 41.5 ksi for 2.54, 7.62, and 12.7 cm (1, 3, and 5

inch) thick plates, respectively.
79

5.5 Interrupted (abnormal) cooling, in which the heat transfer coefficient at

the bottom surface changes from the same value as at the top surface to a

zero value, can result in lower property values than found for asymmetric

cooling. For example, for a 12.7 cm (5 inch) thick plate and (sequence B)

C curves interrupted cooling yields a minimum yield strength of 39.0 ksi

compared with 41.5 ksi for asymmetric cooling.

5.6 For "worst case "interrupted asymmetric cooling and for the 2219 aluminum

alloy lot studied here, plates with thicknesses less than about 5 cm

(2 inches) will not suffer yield strength degradation below levels in

Federal Specification QQ-A-250/30.

6. Round Robin Results

6.1 Round robin results show that, for the range of conductivities from 33

to 37% I ACS, an inter laboratory agreement of about =0.6% lACS (at the two

sigma level) can currently be expected. Agreement could be improved if

all laboratories used conductivity standards certified by a single laboratory.

6.2 When NDE measuraments are being made on a sample of 2219-T87* from an

unknown lot, eddy current conductivity measurements alone are not sufficient

to screen mechanical properties. Hardness measurements (or better yet,

yield strength measurements) must be made somewhere on the sample.
APPENDIX A

Listing of the interactive program used for least squares fitting

the data in Table VII to C curves as described in the text of this report.

The language is Fortran V and the program was compiled and operated on the

NBS Univac 1108, The data format called for in subroutine READD for the

data as displayed in Table VII with the exception that the headings

"sequence A" and "sequence B" are removed and END statements placed after

the list of temperature intervals and at the end of all data to be used.

SUAATZtSOTTAUl

)

12

3

4

5

6

7

8

9

10

11 100

12 101

13

14

15 102

Ifi 17

18

19 98

20 103

2122

23 104

24 99

25 97

26 105

27

28 200

29 291

30

31

32

33

34

35 110

36

37 111

38

39

40

4148 iia

43

riAIN(19J

INTEGER UP

CONNON /9U/ IR,IU.R,IPROP _ COfVWW /PAR/ P(10),UP(10),PAD(19),E(10)

CONflON/RD/T ( 1 30 ) , I SN ( 200 ) , HRB ( 200 ) . P IfiCS

(

200 ) . YS < 200 ) , UTS

(

2M ) XRA( 200 ^£L( 290 ) COrWON /RT/ TI(200,i903,NE,NS

IR-S

IU>6

R- 1.3872

CALL READO

WRITE au, 101 ) FORf1 AT(' C CLRUE FIT UHAT PR0PERTV7 " ,/,

t' ANSUERJ 0-EXIT, 2 -XlACS, 3-VS , 4 -UTS')

READ! IR. 102 . ESR- 100 ) IPROP

FCRrtAT( II

)

IFCIPROP.EQ .03 GO TO 112

I-IPROP

IFCI.NE.l.AND.I.NE.a.AND.I.fi£. 3 .AND,I.NE. 4 )G0T0 100

WRITE(IU,103)

FORHAT(' GIUE INITIAL UALUE5 FOR PARAMETERS',/,

X' SIGN, K2 , <3 , < 4 , ICS, SIG3 , FREE FORrAT'

)

READ (IR,104,£RR-98) CP(J),J-l,fi3

FORNATt ) IFCP<1K£Q.0) GO TO 110

UR'^TEtlU 10S

)

FORHATt ' GIUE STEP SIZE FOR EACH PARAMETER. FREE FORMAT'

)

READ(IR, 104 .£RR-g7 ) (£(J),J- 1 ,S 3 UR 1 TE(IU, 201 ) FORMAT!' DO A LEAST SQUARES FIT7, l-VES, 2-CALC, TABLE'

,

X' 3 -OUT TO FILE' ) READ(IR. 102 ,£RR- 200 ) NDEC

IF(NDEC.N£.n GO TO 111

CALL niNLSO

GO TO 290

CONTINUE

GO TO 190

CONTINUE

IF(NDEC.EQ. 3 ) CALL GSDFIN< 3 ) IFCNDEC.NE.a: GO TO 106

CALL GRDFIN(0J

GO TO 290

CONTINUE

END
SUART2SS0fTAt.a

)

12

3

4s

6

7

,READ0<73

SUBROUTIME REAOO

INTEGER UP connow /Ru/ ir.iu.r.ippop

COnnON /PAR/ P(10),UP<19).PAD(10),£(10)

COWJON /RD/ T(10e),ISN<2e0).HRB(a««),PIACS(200),VS(2e0),UTS(2fl0),

ZRA(200},EL(2d0)

COnnON /RT/ TI(20«,10«),N£,MS

9 90 format (' add in tenp. intehual data, folloued bv*.

10 PROPERTY AND TINE DATA")

11 REAO( IR.100)NHO

12 100 F0RNAT(A2)

13 IF(NHO.Ne.'TEM(iO TO 900

14 NB>0

15 ,NE-0

16 91 R£AD(IR.100)NO€C

17 IF(NDEC.EQ.'EN' )GO TO 105

18 101 RCAO( 0,102) N1

19 102 FORNAT( ) 20 NB-H£<fl

21 NE-HE4N1

22 R£AD(0,102) NO,(TCJ).J-HB,NE)

23 GO TO 91

24 c ne IS TOTAL NUMBER OF TEMPERATURES READ IN 25 105 CONTINUE

26 NS-0

27 C NS KEEPS track of number OF SANPLES

28 lie R£AD( IR,100)NHD

29 IF(NHD.£Q.'£N' ) GO TO 901

30 NS-NS+l

31 READ(0,102)ISN(NS),hRB<NS),PlACS(NS),VS<NS),UTS(NS),

32 X£L(NS),RA(NS)

33 NER-NE-l

34 READ(IR,102,£RR-902) (TKNS.JJ.J-l.NER)

35 GO TO lie

36 900 URITE(lu.i20)

37 120 FCRMAT( ' FIRST CARO DOES NOT READ TEMP RANGES'

)

38 RETURN

39 901 UHITEdU.lcl )NE.NS

40 121 FCRNAT(' NO. OF T£?»S. REAO-M4,/,' NO. OF SAMPLES

41 RETURN

42 902 URITE(IU.122)

43 122 FORNATC' ERROR IN READING TIME DATA')

44 RETURN

46 END

SUARTZXSOf-AL (1 ) . fli NLSQ ( 9

)

1 subroutine ainlsq

2 DOUBLE PRECISION A,AA,B

3 integer up

4 CONNON /RU/ IR. lU.R, IPRCP

5 ccrnoN /PAR/ P(ia).uP(i0).?AD(i0).Eci0)

6 CONNON /RD/ 100 ) . ISN( £00 ) ,HR3( £00 ) ,PIACS( 200 ) ,y$( 200 UTS(200 ) 7 XfiA(£00),E’.C£C0)

8 CONNON /RT/ *1(200, 100). n£. NS

9 CONNON /LSN/ a( 1 0, 10 ) , AA(10, 10 ) , 3(10

)

10 OINENSICN S:GC(290).rSI(2e0).SN£N(£00),5?(£00).2(10.200),C(10)

i: C PICK PARANETESS TO 3£ UARIED

12

13

1415

16

1718

19

20

21

22

23

24

25

26

27

£9

29

30

31

32

33

34

JNIT-0

101 U9ITE(rj,102)

102 FORNAT(' list PaRANE'ERS TO BE 'JARIED'./,' l-SIGrt , 2-<2.

X'3*<3. 4-<4. 3*<5. 6-SIG0. BLANK -RETURN, FCRNAT SIl')

REAO( IR. 103. ERR- 101) (UP(J ),J-1,S)

103 FORNATCSIl)

NPV-0

DO 104 J-l.S

IP(UP<J).£3.0) GO TO 10S

104 NPU-J

105 IF(NPU.£3.d) RETURN

2011 JNIT-JNIT*!

NOIT-0

202 continue

C ZERO LEAST SQUARES NATRIX

DO £06 J-l.NP'J

DO 205 <-J,NPU

A( J.O-0.

205 A(<.J)-0.

£06 C(J)-0.

C

C EUALUATE PARTIAL DERIUATIUES

C
36

3i

s

39

4«

a

43

44

S

47

4t

49

S9

61

6a

63

54

55

56

57

58

59

68

61

62

63

64

65

66

67

68

69

78

71

72

73

74

75

76

77

78

79

38

81

82

83

84

35

88

87

88

89

98

91

92

93

94

95

96

97

98

99

188

181

102

183

184

186

186

18?

188

189

118

111

112

113

CALL CALC(SICC)

00 287 J«l,NS

IFdPROP.EQ.l ) PSI(J)«HPB(J1-SIGC(JJ iFdPRop.eo.a) Psi(j)-piAcs(j)-siGC(j)

1F(1PR0P.EQ.3) PSK J)»yS( J]-SIGC< J)

FSI(J)-UTS<J}-SIGCU)

887 S«En(J)«SIGCCJ)

DO 289 J«1«KPU

JDO-«JP<J)

P<JOO)«P<JDO)-*£(JDO)

CALL CALC(SP)

DO 288 I-l.NS

2ti z(j.n-<s?(n-siGca))/E{jDO)

P(J60 3-PUDO3-€U00)

289 CONTinuC

C

C FILL LEAST SQUARES HATRIX

0

DO 213

00 211 <-J,NPU

00 218 :-l«NS

218 A<J.K}-A(J,iO>Z(J,nxZt<.Il

211 A<IC.J)-A<J,m

DO 212 I-l.NS

212 C(J)-C(J3+PSICI)XZ(J,I)

213 CONTINUE

DO 214 J-UNPU

214 B(J)-C(J}

CC INUERT riATRIX c CALL DPINUS(NPU,+1,ISIG)

WRITE (IU,1004) ISIG

1884 FORHATC' DPINUS CALLED. ISIG-M3)

C

C IHCREHEHT NO. OF ITERATIONS

C NOIT-NOIT + 1 IF(ISIG.N£.8) GO TO 101

DC-8

DO 216 J-l.NPU

21S DC-DC+ C(J)X8<J3

1F(DC.GT.8) GO TO 218

DO 21? J-l.NPU

217 B(J}—B(J)

218 J-8

219 J-J+1

IF(J.GT.S) GO TO 228

PAD(J)-P(J)

GO TO 219

228 CONTINUE

DO 223 J-l.NPU

JD0-UP(J3

IF(DABS(B(J)).GT.ABS(18.xPAD(JD0))) GO TO 223

2238 IF(OABS(B(J) ).LT.ABS(8.5XPAD(JOO)) ) GO TO 2231

B(J)-8.5XB(J)

GO TO 2238

2231 PAD<JD03-PAD(JOO)+B<J)

223 CONTINUE

224 CONTINUE

V8-SOE<(P3

VT-SOE<(PAO)

IF(YT.LT.V8) GO TO 229

URITE<IU,10063 NOIT

1886 FORHAT(' IT. NO. ',14,' CHI SQUARE FAILED TO INPROUE'

3

GO TO 181

229 URITECIU, 18983 JHIT.NOIT, (PAD(J 3,P( J3 .J-l.S

3

00 238 J-1,6

238 P<J3-PAD(J)

1898 FORTWTC' S£0.N0.',I4,' IT.NO. ' , 14, /, X' NEW PAR. UALUES PWU. PAR. UALUES' ,/, ( 2E12.4 )

)

UH1TE(IU,1831 ) yT

1891 FCRNATt' LEAST SQUARE ERROR-' .£12.4./.

1892

X' DO ANOTHER ITERATION?.

READ aR.1092) NTEST

rORNAT ( 1 1 ) IF(NTEST.EQ.l) GO TO 282

GO TO 101

E?4D

1 • YES')
83

SUMrrZSSOfTALCl

18

3

4

5

6

7

t

9

19

11

13

13

14

15

16

17

18

19

39

31

32

33

34

35

36

37

38

39

39

31

33

33

34

35

36

37

38

• ll

41

43

43

44

48

49

51

S3

53

54

65

56

57

58

59

69

61

63

63

64

65

19

15

39

35

36

38

35

49

46

69

55

69

66

68

?9

88

95

139

159

139

).CPIMUS(3)

SUBROUTINE DPINUS(N.<,ISIS3

DOUBLE PRECISION R.AA.B.C.hOLO.X

connoN /LSiv a(19, 10 ). *»a< 19,10), sae)

cormow /ru/ ir,iu,r,ifrop

ISlG-9

IFdC.LT.0) CO TO 39

00 15 I-1,N

00 15 J-1,N

IF(I.EQ.J) CO TO 19- AAa.J)-9.

CO TO IS

CONTINUE

00 65 L-1,N

00^5 J-L,N

X-DABS(A(J.D)

IF (X.LE.C) GO TO 35

C*X

J1*J

CONTINUE

IF((C-1.0E-8).L£.9. ) GO TO 139

IF(Jl.EQ.L) CO TO 49

DO 38 J-L.N

HOLO-A(L,J)

a(l,J)*a(j:,j)

A(J1.J)-HOLO

IF (IC.LT.0) GO TO 35

DO 33 J-1,N

H0LD«AA(L.J)

AA(L.J)-AA(J1,J)

aa(ji,j).holo

IF<IC.tQ.0) CO TO 49

HOLD-B(L]

B(U<B(J1)

BtJl )«HOLO

CONTINUE

DO 60 I«1,N

IFd.EQ.L) CO TO 69

21*A<I,L)/A<L,L)

DO 46 J-L.N

A(I.J)-A(I,J) - 21XA<L,J)

IF(<.LT.9) CO TO 55

DO 50 J-l.N

PA<I,J)«AA(I.J)-2iMa<L,J)

IFOC.EO.0) GO TO 69

ia)-B(I)-2lXKLJ

CONTINUE

COffTlNUE

DO 95 L-l.N

21»A(L.L)

DO 70 J-L,N

4<L,J) • A(L.J)/Z1

IFOC.LT.0) GO TO 86

DO 75 J-1,N

AA(L,J)»AA(L.J)/21

ircK.Eo.a) GO TO ss BCD-BCD^Zl

CONTINUE

GO TO 150

ISIG —1. WRITECIU,130)

return

rORf1AT(///30X,4SH 1ARTIX IS SINGULAR, NO INUERSE OBTAINABLE ///)

END SWA9T21S0FTAL ( 1 ) . SOEK ( 4

)

1 FUNCTION SOEK(PIN)

3 INTEGER UP

3 coNNON /RU/ :r,:u.r,:prop

4 CONPON /PAR/ P(iaj,U?(10).PaO(10),£(10)

5 COPrCN /RD/ T(:D0),:SN(c00),HRB(£00),PlACS(200),yS(3003,UTSt300),

6 XRA(399),ELC300)

7 CCNHON /RT/ TI ( 300, 139 ) ,NE, NS

8 DirENSION PIN(10),hOL3(i0),SC{3e0)

9 SGEK*0.

19 DO 1 J-l.S

11 HOLD(J)»P( JJ 13 1 P<J>PIN< J)

13 CALL CALCtSCJ

14 00 2 J-l.NS

IS IF(IPRCP,£Q.l) V-HRB(J)

16 IFdFROP.tC.23 J3

1? irdPRCP.£Q.33 J 3 18 IFdFO0P.£Q.4) '^•UTSCJ)

19 X«v-SC( J3 39 3 SCEX-SGEX+XIX

21 XN-NS

22 SCEX * SORT ; SQEK/ ( XN-63 3 23 CO 3 J* 1 ,

24 3 »(-'3-mOLO(J3

25 RETURN

26 £N0
SVMRT2XS0FTAL

1Z

3

4

5

6

7

8»

It

1112

13

14 C 15 C

16 C

17

18

19

29

21

22

23

24

25 2

26

27

28

29

39

31

32

33

34

35

36

37

38

39

Cn.CALCO)

SUBROUTINe CALC(SC)

INTEGER UP

COnrWN /RU/ IR.IU,R,IPROP

COnrWN /PAR/ P( 10 ),UP( 10 ),PAO( 10 ),£( 10 ) COnnON /RD/ TC 100 ),ISNC 200 ),HfiB( 299 ),PlACS( 299 ),yS( 200 ).UTS( 200 ), »RA( 200 ).EL( 200 ) COfffWN /RT/ TI(200,109),NE.NS

COftnON /TP/ TAU(2ad)

OiriENSION SC( 209 ),£CALC( 299 ) XX»AL0G(P(23

)

T9- 273.15

CP-P( 3 )XP( 4 )XP( 4 )/R

CP2«P( 5 )/R

CALCtWLTE TAU'S

H6R-N£-1

DO 2 <M.MER

TEflP«(T(K3+TnC+l))/a.

D1 • (T£nP+T0 )X ( P( 4 )-TE?1P-T9 )«2

IF(Dl.LT.l.£-35) Dl-l.E-35

D2-T£nFHT0

ECALC(<)-XX + CP/Dl + CP2/02

IF(ECALC(<).GT.S0. ) ECALC(<)»50,

IF(ECALC(ICKLT.-S0, ) ECALC(KJ—50.

DO 3 J»l,NS

TAU(J)-0.

DO 4 <-l,NER

TRUCJ )-TAU(J J.)aXE>P(-£CALC(lC))

CONTINUE

CONTINUE

DETERNINE THE CALCUATED UALUE OF THE PARANETER BEING FITTED

DO 5 J-l,NS

IF(TA(J(J).GT.50. ) TAU(J3-50.

SC(J)«<P<i)-P<S):aEXP(^TAU(j) j P<6)

RETURN

END

SUART2XSOFTAL( 1

:

12

3

45

6

7

8

9

10

1112 101

13

1415

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40 106

4148 lit

43

102

103

104

105

.CRDF1N(123

SUBROUTINE GRDFINdDECJ

INTEGER UP connoN /Ru/ ir.iu.r.iprcp

connoN /PAR/ pa0),uP(i0),PADaa5.£ci0)

COnnON /RD/ T( 100),ISN(£00J,HfiB<200),?lACS(200),Y5C200),UTS<200),

XRA<290),£L(200)

COWlON /RT/ Tn2Ca,100)>NE,MS

COmON /TP/TPU(200)

DIfTENSION SC (200)

DEFINE FILE 3(204, 120,-1, NAS)

URITEdU.lOl ) (P<J),J»1,S)

FORNATt' PARAMETER UALUES ARE

t

X' X2-',£10.4.SX, ' <3-',£10.4,SX,

X/, ' <S-',E10.4,5X, 'SIG3«d£10.4)

CALL CALC (SC)

10

10

10

:o 10

d/,' SIGN*", £10. 4, 5X,

<4-',£10.4.SX,

IFdPROP.EQ.l)

IFd?R0P.£Q.2)

IFdPR0P.£Q.3)

IFdPROP.EQ.4)

UfiITE(IU,ie2)

'' HRB^

XIACS'

i' y.s.‘

'^U.T.S.^

TAU'.8X.A6.7X,'CALC. UALUE'

)

FORNATC' SANPLE N0.',2X,

DO 103 J-l.NS

IFdPROP.EQ.l )URITE(TU, 104) ISNU).TAU(J), HRB<J).SC(J)

IFdPROP.£Q.2)URITE(IU,104)ISN(J),TAU(J),PlACS( J),SC( J)

IFdPROP.EQ.3)URITE(IU,104)ISN< J),TAU(J), VS( J),SC( J)

IF(IPROP.£Q.4)URITEdU.104)ISN(J),TAU(J), UTS(J),SC(J)

CONTINUE

FORNATt I4,3E13.4)

yT-SQEK(P)

uRiTEdu.ies) yr

FCRNATC' NCRNALI2ID LEAST SQUARE ERROR-" ,F10.4)

IFdDEC.N£.3) RETURN

FIND(3"1 ) yRITE(3"NAS,102) 10

DO 106 J-l.NS

IFdPROP.EO. 1 )URITE(3'NAS,104):SN(J),TAU(J),H98(J:,SC< J)

IFdFRCP.EQ.2)USITE(3'NAS,104)ISN(J),TAU(U),PIACS(J ),SCCJ)

lFdPRC?.£Q.3)LRITE{3'NAS.104)IS^^( J),'AU(J),VS( J),SC( J)

IFdPRCP.£Q.4)URITE(3'NAS,ld4)ISN<J),TAU(J),UTSlJ),SC(J)

continue

URITE(3'NAS,110)

FORNATdH ,'£N0 ')

RETURN

END
85

ACKNOWLEDGEMENT

We are indebted to W. F. Brown of NASA-Lewis, G. A. Rodney of Martin

Marietta, S. A. Levy of Reynolds Aluminum, and R. J. Schwinghamer of Marshall

Space Flight Center for their aid in carrying out the round robin measurements.

We thank C. H. Brady for the metallography presented in this report. The

efforts of P. A. Boyer, R. L. Parke, and R. D. Robbins are also greatly

appreciated. We also thank J. J. Fillibin for his aid in plotting and

analysis of the data. We would also like to thank D. E. Newbury and

B. r. Diamondstone for chemical analysis, C. J. Bechtoldt for some x-ray

’

measurements, and R. F. Boisvert for advice and assistance on the heat flow

calculations. Appreciation is also extended to R. V. Drew, D. E. Harrison,

D. M. G. Summers, and L. J. Toms for the preparation of the manuscript.

Finally, we are indebted to Dr. S. A. Levy and associates of the Metallurgical

Research Division of Reynolds Metals Company for frequent consultation and

for the ingot and plates made available for this study.
86

REFERENCES

1. Aluminum Inspections Pressed, Staff Report, Aviation Week and Space

Technology, Aug. 6, 1980, p, H.

2. Aluminum Concern Extended to Testing, Staff Report, Aviation Week and

Space Technology, Aug. 13, 1980, p. 17.

3. M. C. Flemings, Solidification Processing, McGraw Hill, New York, 1974.

4. 6. Phragmen, J. Inst, of Metals, 77 (1950), p. 489.

5. Metals Handbook , Vol. 8, ASM (1973), p. 126.

6. F. Keller and G. W. Wilcox, Alcoa Research Lab., Tech. Report ft (1958).

7. R. L. Myklebust, C. E. Fiori, and K. J. F. Heinrich, NBS Technical Note

1106, U. S. Govt. Printing Office, Washington, D.C., Sept. 1979.

8. L. F. Mondolfo, Aluminum Alloys: Structure and Properties , Butterworths

,

Boston (1976), p. 491.

9. R. Mehrabian and M. C. Flemings, Met. Trans., Vol. 1_ (1970), p. 455.

10. W. L. Fink and L. A. Willey, Trans. AIME, Vol. 175 , (1948), p. 414.

11. J. W. Cahn, Acta Met. Vol. £, (1956), p. 572.

12. J. T. Staley, Industrial Heating, Vol. 44, (1977), p. 6.

13. J. W. Evancho and J. T. Staley, Met. Trans., Vol. (1974), p. 43.

14. J. W. Cahn, Acta Met., Vol. £, (1956), p. 449.

15. W. Wilson and L. J. Swartzendruber, Computer Phys. Comm., Vol. 7_, (1974), p. 151.

16. R. C. McMaster, Nondestructive Testing Handbook , 1959, Ch. 42, p. 18.

17. H. V. Pellegrini, Metal Progress , March 1980, p. 60

18. A. Chitty, J. Inst, of Metals, Vol. 8_6, (1957-58), p. 55.

19. S. Matsuo, Trans. Nat. Res. Inst. Metals, Vol. 1^, No. 2, (1971), p. 57

20. Y. Baba, Trans. Japan Inst. Metals, Vol. (1969), p. 188.

21 . W. A. Denn, A1 uminum, Vol. 1_, Chap. 6, American Society for Metals, (1 967).
87

22. G. Thomas, Transmission Electron Microscopy of Metals , John Wiley & Sons,

New York, (1962), pp. 153-158.

23. H. K. Hardy, J. Inst. Metals. Vol . 79,, (1951), p. 321.

24. J. M. Silcock, T. J. Heal and H. K. Hardy, J. Inst. Metals, Vol. 82,,

(1953-54), p. 239.

25. G. W. Lorimer, Precipitation Processes in Solids, Met. Soc. of AIME,

(1976), p. 87.

26. E. Hornbogen, Aluminum , Vol. Part I, p. 41; Part II, p. 115;

Part III, p. 163; Part IV, p. 166, (1967).

27. V. A. Philips, Acta Met., Vol. (1975), p. 751.

28. H. S. Carslaw and J. C. Jaeger, Conduction of Heat in Solids, 2nd edition,

(1959).

29.

J. M. Hyman, LA-7595M Manual, Los Alamos Scientific Laboratory.
88

Table I

Center and Near Edge Comoosition of 12.7 cm (5 inch) thick 2219-T851

Aluminum Alloy Plate (Reynolds Lot No. 7950777-01).

El ement Composition (wt%)

Approximately

2 cm from edge Center

Cu* 6.6 5.8

Cu 6.5 5.9

Mn 0.36 0.35

Fe 0.24 0.21

Si 0.071 0.064

Zn 0.033 0.030

Ti 0.030 0.041

V 0.070 0.079

Zr 0.11 0.12

Ni 0,029 0.029

Mg 0.010 0.009

*Values determined by solution molecular absorbtion spectrometry

,

others by emission spectroscopy.
89

Table II

Solidification "Path" During Formation of a-Aluminum Phase

C^^wt% CL®wt%

0 6,30 0.3 0.20 0.10

.1 6.87 0.30 0.22 0.11

.2 7.56 0.303 0.25 0.121

.3 8.44 0.306 0.27 0.136

.4 9.64 0.309 0.33 0.156

.5 11.22 0.312 0.394 0.183

.6 13.48 0.315 0.49 0.222

.7 17.13 0.318 0 . 65 , 0.29

.8 23.94 0.324 0.97 0.41

.85 30.43 0.330 1.28 0.52

.9 42.58 0.336 1.91 0.74

.95 75.66 0.348 3.766 1.35
90

Table III

Summary of Etching Response of Phases in Cast 2219 Aluminum Alloy

Etchant CuAl (^oiJnded

^2 irregular) Cu^FeAl^ (blades)

unetched light gray slightly darker than CUAI2

1/2%HF 15s @ 20°C no attack outlined - dark brown

l%NaOH 15s (3 50®C light brown no attack

10%Na0H 5s @ 70°C violet brown light brown

25%HN03 45s 0 20°C dark reddish black dark blue gray to black

20%N2S0^ 30s 0 70°C no attack no attack

H3P0^ 60s 0 50°C no attack - outlined no attack - outlined

Keller '

s

outlined - not colored outlined darkened
91

Table IV

Examples of Electron Microprobe Analysis of Phases

in Cast 2219 Aluminum Alloy

wtS A1 Cu wt^o Mn wt^o Si wt% Fe

rounded irregular (CuAl^) 51.3 49.5 0 0.4 0

blades (Cu^FeAl^) 53.9 36.3 2.2 0.4 8.6

CUAI

2

exact 45.9 54.1 - - -

Cu

2 FeAly exact 50.8 34.2 - - 15.0
92 I

r«» p«* >o oo oo o o o o o o

>>o

r— t/1 r— (U (O 3

b'Z 3 >

<U E <o 3 U

(Q &

Hc ^ r>» « aj a S. I R3 2 rrx -=.2

cvi CNJ a, 3 f-

+J 3 C

(ti xi a) 's.;s > u (U a) Eu

un

CO

0) J=

fOc

o. s_ O (U O 4->

(/> o

4->o

<uQ.

(U a

0) +j

<au

l/l •!— o

<4-

UiO

I— c CL O. O 3 E •»- a

<o w’

(/» V5 • T- >1

oj E O a at rS- rJC >» <T3 •M L3

to

t4_ -a -r- o <u -£= M +-> to >» I— ^ Ml ro O

>»

f*“ (O o

19

U

C 4) rt3 < S_ “O 3 C

'W 3 ro O

to to +j 0) i. <— <a 3. ^ S- a fo o

Qi LO <4-

c* oo oo o o

-^r o

oo oo o o

ro -*3* oo QO o o• •

<cr to o o

tn rf- o o

uo lo

rr "«T o o

tn Ok C%

C to CM CM CM

Cvi

O

O

O

O

O • « • • •

Ci <3

CM CM O O

ifi CM CM o o

CM ^0

CM CM o o

vO CM

CM CM o o

to •-) to CM CM CM o o o o o o o o o o o o d23U

Tf CM tn ko UO CM

CM o o o o o o o o o o o o o • • • • • •

CO ^ to ^ uo ^ to CM to to to ro to to • • • • • • • m c3 rH O 00 to vO CM to CM CM CO • . • • • • • vO vO vO vO vO vO 'O 1 o to

aj CM o o

u. • • • m ^ 'a* ^ o o o o • • • •

UO oo CO

f-t o o

CO oo o o

CO CO o o

LUa o
93

Q CVt P ^

(U 5 °

(U 0> 4-> C no 'q. O ^u

"O •*“ 2 rO «

UJ

_iS3<

*o

O

>>i^

•->

n •»- VO > • •«- o -«-> u ns 3-3 «- - O O 4-» c

73 a)

-a U) 3

</>

w

a>c

•T3 *> • W (T5 >>

PO CJ o <4- F— fO O <T3 U £ ^ 3 i

12 5 '— " "D 3

i':;

® 0 ®® 0 ®®O 0 T'tD®®C^'r®®CDCD 0 ®CDC3fc ncn n 'T LAID C^P*- m cn nn nn n n 2 O®O®O®®®®OO®OO 0J®OLDCn®OCU-«-*

UJ

CDT® 03 CO CD CD®

*—

r-c^ CD CO TT o

UJ ®O®OO®®®® 00 «hOO(U(DO®C^OOOC*MU

a.

X CD ID CD 4-4 03 TID o> r- o r- r*- COCO T T X UJ UJ -J ®®®oo®®oiDncu®‘v®'T®cocDCDocno»r- 3 1-4 O CD •<r TID ID CD® LD r- p-r^ X ncn cn n n n n n n n n n o UJ X t- ®ooo®®o®r^cocD®ooniDonoon®ooo'^

Ui^ o CD CD CD 4-4

nC3) T 00

T r-

®

n « t- J <t

H- t^r-r- fw fv-<D

®®®

TTT 0. UJ CD ®®®®®®®®OJO3 ®® 00 niD®lDC^n®®'^CD

QCX

a t- CD CDLD

® <7) 4-4®

T ru 00T

UJ XC5 X D- D- CD®®

®

®

TT

X XOX *-i *-• O t- *-• X ®®®®®®®®CDlDCD® 00

C04-*®lDO3 O3 ®r^D-r^

UJ •—• UJ UJ o o *- q: o <r

®

®

® —4 4h 03

nn

n

®

®®

UJ

X (- <C E K «J CD

nnnnn

nn

n

nnnn o (E (E ^4 ^4 CO Ln oo

CD CD a: UJ Ul

X

<x UJ t- (- UJ

n CD uo (D ru r-® 03 P- CD

®

q: f-* u. u.

CE UJ U. <£ <C <Z

ID ID LD ID LD CD

T

T

Tnn

n

Ol-X J- o O

®O

O «S

OO 00 fUOO rO CD® rVT 03

® 03 CD o

U.U. CD CD <X CD O O CD -4 CD n* LD 03 (S.® P- CD® o <t<i: <x ID CD ID LD LD LD T T T nn n

(/)(/) <I K-* t-H 3 o o o ®

® o <s o fo

m Lftm in -T c3>r-o Ln r-<D <x) <z<zx

*z ^ ^ ru ru ru oj cnn

n Ln Lo U) Lf>

p-* ^flQCQuj nmtnnnnnnnnnncncnm ca oa Qi cn e: % ^q; X X UKD o o <o ® ® r- oj o ru n fu r> -I® fn o ® 'T '<r Lo oi

nj ncQx cc CK Qi » % 3 ® CO C7) CD 00 CD C7> CO 03 cn 00 to r>-

m o oj

m oj 03

m ^ XX ^cQ os CD ro tn m n n n n m (n -X n n n n n n n tn ru ru cu oj

OQ QC QC <x <t 4 -*Qc X X ui 00 oj 00 o o o 00 00 fu cu r- (7>

n

r- C7> r-® CD '^oo 03 • OOCOX X

Qc q: Qc -- r> CD C7) CD LD 00 r- ru

® o) a> C7) C7) -f4 (!

m o —• n T-i 03 '^ujxx — 'rr^omc^nfnnnnn'^'T'Tmcomnncncnnruojruru E •• •• -H CO ”T n n m pT n n m Tn rn T CO 03 fu n

UI 3 LO 00

ox QXXCErnnrnnfnrnnnnrnrofnfnnfnc^nfonfnfnnn z o Q X X <t X n n n n n m n n n n n cn cn n on ro n (n m n cn

Ul UJ

X

X <i t- 3 F-J <x <r ^ » ID o CD

m r- »-i r*- <s a» o* 00 Dm CD

n r- o r- <s cn 00

O Q_ »mCDCD

UJ E ^ 'O UJ 00 00 00 00 0- 00 CO CT> r» 00 00 00 CD Ci 00 (7> (7> 00 C7> O)

CD <X 'r (>- rw fs. [V_ [V- {V- (V. fs. C«^ (N. (V. fv. (V. CD ^ ^ <I ' ^ ^fU ID O cn 0» O O O O ® 00 D* <S 'T ® m O 03 CD

^D3 00000<SO>®®C7)0®C7^CD®<SCDO><SO)00>®<D

CD CD CD CD CD

X 00 r- 00 00 00 00 00 r- 00 00 r- 00 00 D- 00 r- 03 r- 00 D- ZXXXXXXh^ ZEEEEEE 03 tn ID CD r- 00 O 03 n ID CD r- 00 CD O 03 n

^3 -X ^3 ^4 ^4 4^ 03 03 03 03 03 IIi! o o o o o o o

CO CO CO CO v*4
94

I

6>0<DLftO<D'^r-OOCOr-<S<3>0<S®<S<SLfJO®r^<SO<St^CQOOCO'»-«OOCOinOO

n n T m m tn t ir> ^ t cn tn r-<o n n n n n n n rn nm mn n n n n

®onc^oooooooooo-^oo<soooir>r-oocncooocaoooococo<s<3'vinoo

<o<o co<o into m nj -r-» nj n oo^ oi-^

r-r- r-r- r-r^ r-r^ r-r^ to r- uxn

oo o 00 o o c'” n o o (u rn ® <s <s <s <s o o o ^ o o o oo ru o o <s t'~ o o ru c*) o o

<o<o u) (D (D cnoj cu n- T ^ -r-i r-r^ r-r- r-r- r-r- r-D- r-r- p-r- uj«)

®u>'T-«®cxj-rHooocncoa>oo
o®Tr^
ocxjtnfno’Tcnc7>
aj-^a3
r)ruoooo

cncntn tn-rn nnn 'T'^lo T^rcn U)U)U) (XJioto U3

tn n n tncntn m m tn ntntn tnmtn tntntn tncncn tn tn m tn oi^cnr^otn«-«'»HO<nr^ooo®ootvii^cnofn(n®oo3tuo>OT®oocoocootu

tof^co iDcor- ’'TLOLO (U'<-«cn u>ruo> futu loooco oojo O) r-r-r- c^p-p- p-p-p- p-p-co p-p-p- tDtotx) tucoco u> ooo'^'r-io^otuooa3tooooo®(D'«-m30coofnoajfnp-<sonjoo^'roooo

inp-tx) top-iD p-tDto ojojo] ojato) •vruai p-cdo oo P-P-P- p-p-p- r^P-P- P-P-(^ P- CO P-t^P- COtOP- LOCOCO LO OCDTOO^OOtOOP-<OCr><SOOOOO»0>tO®LnOO®OlOO>tOO^(n^OOOP-0)0'^

OiCiOt OlOiO o) O) (7) <s o o o o o o <s fu fu txi tntntn

fututu funjfu njfiifu tntntn tntntn tntntn tntntn tntnm m

ou>p-fn
ootup-oajcooooo<sootucooooLnTruon-»-«coo'r®tnonjtntoopt7»'-«tn >-4Cooo p-cDO u)P-<o CTJCOcn n'toco n'tU'v oxsui co tncoto COIDLO LOLOCO U)U)lO LO LO U) LO LO LO LO LO lO LO LO n* 'T OlOOJt7)OP-lO’TOOOCOOOOO®0-*H^OlOOCO<SOOLOP-®OOLOCO<S>0-^OOm

00 00 ci CO to 00 oo-»-*p- fUN-oo LO LO o o tn n-tup- cdooplOLOlO LOLOLO LO CO lO LO U> LO lO LO CO LO lO LO LO LO LO T T 'T C0P-L0-.HC0l0CDl0l0L0L0C0P-0)00P-C00000L0'r'TC000C0P-00C00)0iOJ00*.-^fU^'^OO)

(ntnfntntncncntncnmtnfnfnmcnfntnmtnfncncntntntncncncncncncncnmtncncn m

(najcDiooooLotn<.-*o>p-p-ajooo>o>p-aifnocU'^co(no><oiootn^-»-«ofu<stnco®oo

oooooo—iCT>®p-p-cacT>cop-fn'^^'^p-LOLOC7)ooTH>riooa»LOP-LocDfncacoLoon’ tnn-Tfn'Ttn'TtnfntncnrnfntnfncnfntnfncncntnTTfntncntncncnfnfnruajtnnj nj

ooop-ioP-''-ip-p--^(n®'^oofuooiocoo)tn®ojiop-otncofUP-^'r^'T-i^tn®oofuop-

•«r*-i(U’-^o<Dfncomfucucon"mcocDfun‘P-p-p-oc7iO)OP-r-critucDCDP-rup-'*-»co rn tn-v'TTT^n-fn'rTn'fncn(nfncn(n(nfn<nmTfn(n'^(ntntncnfn(nfnfnt-*cn'<-i tu tutntn-^(nnjLOfu-^-<(nfnnjfncofn(OP-ooLOLoan^p-cor^p-Lotn»-ttncuajcuaj>^-«'^

tntnfnntnfnncntncncncnfntnmcntncnnfnfncntnfnmmtncnntntntntntnmmfntn tntncnmcnnnncntncnnncntncnmnnncncntnfncntncnnnnrncnncnfntnfnn

tucooooo^'Tajoionjcotn^tntnoO'-t'^ocofnioajLOcnCTJOOcooooco'rcO'^mo)

00 00P-P-C0C000P-P-00 00 C0P-00 00 00 P-P-P-00 03Oai00CT0>'Sa>P-0)C7)®P-CnC3)OC7)O

p-p-r^p-p-p-p-p-p-r-p-r^c-c^r-r-c^r^r^r^r'-r-p-p-p-p-oor^p-p-p-oop-p-c^oor^oo

®tnp-wc7iotno—•p-p-ruLOtn(no(7>cocoo)fncofULOO>ocDOO)on3®oo)-^ooooo

00>0)OCnOC7>OOCT>C7)CDC7>000<SCOOOLOOaC7>OOOiO)OO^OP-0»OiO>0)(7)0)OiO<S

oop-p-oop-oop-oooop-p-p-p-p-oocop-p-p-p-p-p-p-r^p-oooooor^p-p-p-p-t^p'p-cooo

iocop-ooc7)0—<ojtnTLOcop-030®0)0'«-*fUP-ooa)®fnn-LncQ^rufn’viotDP-ooo>®

nifutviajojrntntncntnfncntntntn'rcop-p-r^p-r-p-caoicncnoioocacooooococnooo-rH
95

ajnoocn(noonjno<®<soo
ooocnooo>cDOor^'rooooo30 ooo<sonu3 p- OQ CO in m cn m n n n n n m (D co n n nn n n n m nci (nn n n n n n o

•-•oooooo^ooiDnj®<S'vnoo-"-»<s<s®Lnrn<s®m(TJOOooo<SfUP-®o<D®

r-oo to tor- to to ct> o r- co r- oo oooo o oj to in

lAin to to r-r- r-r- r-c- r- r- r-r- r-r- r- r- to to

oinoofn—•®<sLnru<s<sna) 0 
c7ifUOoaia) 0 <sr-oo<s»®r-tooor- 0)Ooin'T

r- 00 to r- in r- r- to oooo oor- r- r- r- r- -h oj lo

u) in to to r-r- r- r- r- r-r- r- r- r- r- r- to to

® 0) 0 o»r-o»or-c7)o>oc7»r-oiou>r-ajo®o)'-^®a30 ior-to(onoioio>-^ootooo

r*to ininu) tntnn njnn mnn main ntncnmnoin toinio

m n m n m mnn n n n n n n nnn n n n n n n n n n n n n n

too inor- a> r- r- o>o»r- oocnoo moooo r- ct> o to r- o C7» ooo-^

loto tototo r-r-r- r-r-r- r-r-r- r- r- oo r- oo r- r-tor- tototo

u)ooooooooinoooo-«-<oO'<-«--iO'*-<otoO'<-«cvic\jO'^toinoo>r<-o>oooLn

tooj (ooooQ Qoooo oor-r- tor-o» oinoo r- cn C7> o to in oo ot^-ri r-inm imn tototo r-r-r- r- r- r-r-r- oor-r- r- r- r- oo r- r- r- c^tor- tototo

u)toooooo<3>oo-HO)ototornoo) 0»a»®tDtor-OLniotor-inoo(oomtor- 0 'T'«-*oj

fumn C75 o (7) Q) (71 o 01C710V C71 C7) (71 (71 (71 (71 (71 (71 (71 (71 nmn cncn mncn njmtxi rurum runjru (\iru(u ru oj ru cu nj (\i nj n nn n cn n

®ooo®to-Hocar-o<smo—^oioouno®Lnto<son--^T'(S<ST' 0 --^r-®®^ooto

lom ^to® OOOO) 00 0(7) CTIOO 1/100(7) 00 oo 00 OJ —* r)(7iaj OOCOCT)

LD u) in to u) in to in u) to to ininin to to in in to to lo-rin

®o®<saj©or)ton®m(nin«su)®®®tD'^aio<su)<sto®mooajcorn®no(7) 0)0 0(7)0 (DO 0-^0 o o in r

- 00 (ti oo fu oo ra C7) —• ru ai (d tc (D

(*) tn^in inioto tototo totoin ininin in in to in u) in u) ininin

C7)ooor-r-r-^inr-to^rummor-tor^o^in^O(\jfu^tointOLn—<-^cuDOoor-rcnmmoooooooo ooo ooo o o o o o o o (\i (\i m nj m ca n

cn m c^mtDfacannnncaca nnn n n m m n m cn n m cn mnn

0)no(7)oooLn^coi/)innjr-(\jonr-nofunooooor-ajru^ooa3 -^^(D(ijo^ajC7) nn to in in ru n n n (D r* OJ nooi oooo ru r- (D to to n (Tior-

<U(U ru (u fu n n n^ nnnnnnnn tunru

(7)^OLnninin-Hrun(uooinooooo(uooor-o30ooruinntoinoonin(UC7)0(3onto

n 00 p- r- to o m ru o in ru ru-^<D o (D o n n in to r- n ru ru ru co co r- furu »-• ru (U n n^ nnnnnnnn cutunj —•(unn(U(unrucufu-HO-^-Hr-r^u)innnnnru-^o-^o—•—‘noQC7) 0)oototom^

nnnnnmnmmnnnnnnnnnnnnnnnmnnmnnnnnnnnnn nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn

o)—*^ 0)(7)^to— *n(Do^-^oooto^^(DocuLnO'-^oo»-*^oQoo^'»-*ru(7)in

OOO(D(7)OC7»OOO(7)(DO(Dr- 00 (D<D 00 00 (D 000000 (D(D 00 00 (D(D 000000 <7)Or“{^<7) oooooor-r-oor^co(X)oor-r-car^r-r^p-p-r-r-r-p-r-r-r-r-r-r-r-r^r-r-r-r^r-r-r-roooio(7)'-^cuo(Dtocooo—•r-'-^—ttoruLno^too(7)inooc7)ootoruto^ruootDO

00(7)OOC7)0-^(D(DOOOO(Dr-(D(D(DCQC7)(D(DOO(D(D(DCOCOOO(D(DO)00(DOOOO(7)

oo(3or-(xioor-o3 03 r-r-caoococor-r'r-r^r^r^r-(^r^p-(^r-r^r-o-r-r-r^c^r-r-r-r^r-

»^<uintor-co-^run^(Do-—

»«•—4(UOOOOOOOOO(D(D run^intor-oo(DO'--rum^intor-ooc7) 0 >-^run^in

(7>^^^^^^^ajrururururuajrunjcunnnnnn ton
96

oo(*)LnoooooooHLOoouio>oona)<9ooor-oon^oo'Tcoo^r-r^o9

CO CO tor- to IT) mci 'f cn n n<n

nci n n n n n n dco rn n n n n<*j

ooiooo<socn<oofuo300T^oooLf)0^oo'^noonr-<3<s(7)nootO'»-«oo

®»-i CD r- to LT> <r^ ^ CO r- oor- mm oooo oo rto to r-C“ r- r- mm r-r^ r- r- r- r- r- r- oo®to®oo)cooomajoo'^'^o®nr-®®'»r'»-«oo<nr-®0'*^oi®®^fuoo

® —• coco r- to —• —• mr- oo r- to to oop- oor*- to to r- r- r- r- mm 't t r- r- r- r- r- r- p-r-

®ooxnotoai<-^or*o3to®cnc7icu®co(n<^®(utonop-oon®mm'^0'r(nmoo

tomto (unn nntn p-p-r- r-p-oo tnrum nmcn tnnr) tnntn

(nrun nnn cncnm nnn cnmn cncnn tnocn tnnn oitncn

®-«Hm'^®0)oonoto-^r)®aj®o®mo»'T®'T-^tooooootoaim®o>mp-ocu

o)p-r- i^p-p- nj oj mp-m oooooo totom mcaco totop- ptototo p-p-p- p-p-t^ mmm p-p-p- p-p-p- p-p-c^ r- ooooomp)oo®'^o®oop-tooomcao(uotoooo'r®<^o-^o^toa3om

•iCDCo oooip- ®tom -•^p- DP-to comm p-mru oooocq catop- oo comm p-c^p- oor^i^ mm-r 'T'tt p-r^c^ p-p-p- p-p-p- p-i^p-

®oO'T-»®^r)m®'«rmnotop-coocna30®p-ooo)0(OP-p-OP-p-tooo>»^'^om

0)C7»0) 
 
 o mmm to to to ototo) ooo cd o> oi oio® <s p>nn cunicu ntnn nnn tnnn tuainj pitncn nicucu (utnn tn oo>ooo®aj^ommm®njn30om^ooajmaj®mcumoruCT>oo'TfU'r®to

mmoj ^cop- cDmm vmoo oi cn cn p- oo oo -^mto to t- —• to cd

tomm mmm nmn pjcnn mmm mmm tomto mtom m

oojo(uo>rHr)^omtoco®®o)ooo<;»-^CDono)co®cu®ooocomooommoo®

m to -T- ootooo ® m m m «-< n tnto® r- oo to'^p- m r- o <s oo m

T^'T mmm tomm nmn nnm mmm mmm mmto totom m

®p-top-c\i'.-iajnp-oop-cototop-coa!'r-»'^^n»HCU'maj'rainjnmPip-<oa3<oto®

'^•^•v®®o®®®o®mmmmtotototo®®®®'»^—

r^cncnt^fntntnt^tncnpirnrnfnrnrnpjfHfnrnrnrifnpicnpicncncncnroforncnrocofn

®aj'P“Tnmnnp-'i-*mnpiTnj®®®®o>®®oop-Pip-mfU't-'OOin»-*-*^o)®'r®

tnmni^cDP-ootop-cop-top-P-oono3Piaj®tocDa>>-«amto(Ti'r»ioo(ototoco^‘T‘ ojfUfunnnmnnnmT-4T-i»H-^-»-t — •Tnnnnnnm’^n'^nnnnnnn

®coPiaj®ootomp-mc7)(nTTmcDmm®®®con-^run(nfnp-'»-»®(n®®®to'^m

-^®<-^totoooo)mp-cop-'T-^top-cntonja30)mr^^nna3m®'raj-^cocDootO'r'>r

ojnjfUfnrnrnfnmnron-.-(-.-H-r-4-.-t-.-4 ^•.-•nnpi'Tnnnm'^fn^Tnnnncnpi

tnfnnncumn-tomp-p-totop-p-cop-totom'Tmmf^O)a>oop-oocop-tomma30i04

fnfnornroroc^c^fncirnfnfnrncnrncnrnfntnfncncnfnricnfnpifnrnfnrjfnrnfncnfncn

®to®cocx30)«^ak'i-40o®mtoo®ajco-^oomoo-^ooa)co®'^oooo®a)p-®®®oa®®

p-coo»caoocncDoocop-ooaoooop-p-cooooop-p-oooop-p-cocoootx)oocop-p-toco«tooo

p-p-p-p-p-p-p-p-p-p-p-p»-p-r-p-p-r-c^p-p-p-p-p-r^p-p-p-p-p-p-r“p-p“p-p-p-f^p“

OICO®OJC7>tO--<<OtOP-C7)mC7>®'«H®'^OtO®fUP-tO(00>®T®®®®®O^CO—''»^'»^

00 00 CO 00 00 00 00 CO 00 00 00 00 00 00 00 00 CD CO 00 00 00 00 CD 00 00 00 00 Oi CD 00 CD CD CD 00 00 00 00 00

p- p- p- p- p- p- p- p- p- p- p- p- p- p- P- p- p- p- p- P- p- p- p- p- p- P- P- P- P- p- r- p- p- p00 CD ® fU n m to r- 00 CD ® ru n 4 m tJ3 p- 00 O) ® ^4 03 n 4 m to P- 00 CD ® ^4 03 tn 4

(n CD n T T T T 'T 'T 'T T m m m m m m m m m m to to to to to to to to to to p- p- P- p- P-

^4 •wH « H 4-4 4-4 4^ 4^ 4^ 44 ^4 44 44 44 44 4^ 44 44 44

^f4 ^4 ^4 -^4 4-4 4^ 4H 4 4*4 ^4 4H •^4 44 44 ^4 4^ 44 44 44 ^4 4^ 44 ^4 44 44 ^4

I

I

I

I

I

I
97

n n m n n*n n n ru n cu ru c^p- r-i^

n PI n n nn n n n n n n n n n (*i ®coo®r-cnoooo<s®®«-»(7>rucx3 con®®®<s®o<s(^ 0 '000 <soo®ooo®

<o<o LD LO cn ru t^Lnooi^r-oo toj o> ru r-r- r-p* p- p- p-p-p-p-p-p- imn Tvn

^Lnoooc7v®®<s(i3 <s<s(TjnnoLnnooo<s<s®cu^®o<s<soocu<3 <s<s®o

p-oo p*tfl <Du> oor^oooop-oo noi «^cu

t^p- p- p- p- p- p- r- p- p- p- p- into loio

O 00000000000000000000000 ^ 000000000^00o

0 (7> 0 'TOQOOOOnJOtOrUOOOOOOOOOOOOO)OOOOOCUTC7iOOOOO

cn 00 00 00 p- p- p- p- p- ptn p- 00

p- p- p00 to 00

p- p- p- T LD -r lo tn to

OJ T OJ into u)

CO

pooo<oD>'«^o^rucooooLnooooooooooruooooooiO'^QOoooLO

00p- p- n n 'T‘ ^- p- poj pp• p- OiCTUXi

p- p- pCD OJ "T tn tn LD O 00 (IJ U) lO U) o>

P“ 'T'rotor)(oo*^Toooaj^ruooooooooo<OLn(oooooo(oiDLDOooo

n cn n PI nmn pinn LD to ID P7 n PI LDLDID

n PI p)

'^O(7>'^'»^O 0)'»^^O 0)LDLDOOOOOOOOOOOOOOOOO^t0

CU

o

cn o o o ot 0)PIDLD

to LD

LD LD ID

00 P- ’T

ID LD LD

LD

LD LD LD

P-cn

ID

tn 00

cn

00LD CftOO’^TOJOOOOOOOCOOOOOOOOOOO'^fUOOOOOO'^fULDOOOO

LD T C7» LD P- LO <S> P- T’ O tu IDID LDIDLD (O LD LD LO ID LD 0> O 00

m 'rn

LO

ID 0»00C7)00(7>rUP>LDLD'^00 00a)C7»OO®OP-P-L0f^L0L0L0L0LDLnLDt^L0L0P-L0®®00L0

cinnpinnpipipipinpjpipi O<SOOLDL0LDLDOOOOLDLDLDLD cnncnnnc^nnpinnpinnpjpi PI n

lDlDOL0 L0 P-OO®OCU^fU»-‘O®OO'V®^L0 CUL0 O 0>a>fn'^O-^O^'^®®CUrU

ncDiDLOTiDcoocop-LDairum pinp)PiPiPiPiTP)Pimpirnm LO P- cn P>- O) ^ LD 00 00 00 C7> 00 0> LO fU

OCOO*^®LDP)®'«M»H<SOOOOO®OOOLOfULDnJOnjLOnjLOrU'*^OOOOOOOOiLO

nn'v-xoocoroLDLDLDP-r-'^pi c^nnpipinTT’rnpipipipi LDooooLncna>Lno)>^«sr^ocuLO®cn pipinm-^—

OQ

m tn OiCnOOP-P-P-LniDLOLDLDLDLOOOLOlDP>TP-OOP-P-(nOOOOCncnP-LOlDLOt^LDP-P-lDOOOO

rnnpipinp>nnpipipipinp7fncnrnpinnnnp7nnmrnpip>nnpimnpicnp)p) nnnnnp)P)pirjpipip»npipirrjpipinnnp)cnnnpiPiPiP)P)m(^nnpinfDn

'r^^OrU®»-iO«rLDOfU»^CnLO<S®LD'VOO®ajO'^'^ 00 «SPlLDLOT'm®OP>'XCU'^

oor^cocnoooQr^p-coooooLOoooooocnc^o>oop-p-oo(noooocaoooocxjoooop-oooo(^f^f^r^

®OOOrU-^LO-^r^LOP-<SOOOOC7»OLOOCnOO®T'rLDOfU®OLDOOCUOOO'^LOOO

00 00 ID 00 p* r- 00 p- p- p- CO r- p- p- CO 00 00 cn 00 03 00 CO P- 00 00 cn CO 00 cn 00 00 00 r- 00 00 00 00

p- p- p- p- p- p- p- r- p- r- p- p- r- r- P- p- p- r- p- p« p- p- p- p* p- p- p- p- c^ pID LO P- CO cn ® ru m LD LO p- CO LD LO 00 cn O ^4 ru Pi LO p- 00 cn ® ^4 nj m cn 4 U3 LO

P“ p- p- P- CO CO CO 00 00 00 03 00 CO ru ru ru ru CO cn cn cn cn cn cn cn cn cn cn o o o 
 <s ru ru O o ^ ^ ^ cu Ol ru ru ^4 ^4 ^4 v4 ^4 »4 cu ru aj ru cu fU OJ OJ (U

1 1 1 1 1 1 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 44 44 »4 ^4 44
98

00 P* ^ ^ O O O 9 ^ O O ® O ® O (U O) O ® ^ C'l O 00 O O O Ok O 9 ^ ^ ^ ^ mn <ou) r-oo inu> toui ukuk

f*j<*> D cn nn no nn com noi

o 00 o o 0 0-0 ooooooooooocuoookoooionioO'«^r~-oook(nooom

00 00 ”T'<o.oo<D nu) furu -^^ coo

r-r- u)u) ldu> r-r- (oui <or- v4<DOOOO®OOOOOOOOOO'«^<S>OU)OOOOOOOU)0kOOU)fUOO^0k

cor- r-to 00 00 tnuk -r^oi ukT

r-r- r-p- ujui tncn p-r- uj<d t^<i)

OOOOOOOOfnUJOOOOOCJOTOJOkOOTO-V^-KOOr-OkOOtVirTVOOOfUCO

ncn T^'TLO <0(0 r^r^r- (o<oco ioldu)

fo n nnnn nn nnn nnn nnn nnn

nnoooooooto®oo<&oo)’*-*furuoO'<Honoooo<ooooo>^p-’ 0 <9 oo

p-r- ®o» (OiO'TC^ p-p- <^ntn —lOjru

P-P- OOP- P“P-r^<0 <0<0 LDLOLO P- P- <0(0(0

n<UOOOOOOajOOOOOO'^O^O<S<0'^O(7>'TOO00C0OO<0'7-^OOO<9

p-<3» okoo ukUkP- 00(0 ru'TUk n®-^ ntnco

p-p- p-p- p-p-p-<o (0(0 loukuk p-p-r- <o<o<o oiaj®ooooo®p-oooo(50P-ookOk®oO'r-»oofunukOOk'.-<-*ocop-oo®(unn

o® ®0k0k0k(7k0k ®®*Hn nn loiouk »nfunj nnn rurufu nn nojojojcucu nnnn nn nnn nnn nnn nnn

^okO®oooo(7knjp-p-r-woo-^ajcu®n'r^o®o©®Okn<oo^LDcoon-<-»v

Ok<o nooo--»<»n op-<on3 ooru cop-oo okcuo ©>^00

ukto <oio<o(OLO<o (oukuku) '«r uk •vloio (o<ou)

UkUk00o©o©n®'^ainok©n©oo(3kooono(3kwuk©uk®—•oooooouk'«-^ru

oj-r okooooook okooukfu n^^ lor-oo ^ruoo p--r-»co ooo-h

<010 uk<oi/k(0<oi/k ukukukuk ukuk ”v«r "T ukuk'^ ^uk^r <ouk<o

ooco(ouk<oiikUkP-<o(OTP-p-uk(o<o<o<oukukUk(0'^'T''v^n'r'^TOk-»-»c7ko<oc7kn<o

oo©o©oooooo®®o-<-«<r-i^^nnnnukUkukLnfunjrun3n-^n'^(\ifuajnj nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn

n»-«nnukfuo®®ok®ok'^x-^co'T<ouk'moo>«-i*^<j300'«r®<u^nno©(unfuo

Uk0kP-PP-©0k0kC7kn'i-*a)P-0000(7kP-^00'^Uk(0»HC7)P-P--^-«--«'^O'TUk00P-P-03UkCkk nnnnn'Tnnn-^-mnnnnjnncunnnnrucunjnnnnnjnjaicuvTT'T

o®Uk©p-(0©oo©«-^'^©'r»HUk(0(uuk<o>^-^fu®p-<onj(iiP-''-'Oonooc7)©Ln©©

p-p-cor-«a»(7)0©C7kOka3(xj(7>^ukn^(\jnukU3©o3Ta)nai'^n(o<OLnukLr)Lnca'^ nnnnnnn'r'Tnn'rnnnnnnnncunnajajnjnnnnnjnjnjai^T'n-Ln

00OkOk(7)P-r-00 00P-P-00 00 00<7>O)Ok00P-P-00P-P-C000Ok©Ok00COP-P-P-(XJOTP-00(OUk

nnnnnnnnnnnnnnnnnnnnnnc^nn'^r^nnnnnnnnnnn nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn

^•-<ioo®ooo<ooj(oa>©OkOk(u®CDLfk<?kcnn'va30kUkOk<0'TP-p-nuk®conj(0®

p-<oco(7kcooocooo(a(Xkoop-cop-p-cooop-c7»oooooocxjoooooop-f^p-oop-cor^cop-oooooo p-p-i^r-p-p-p-p-r-r-r-p-p-p-p-p-p-p-p-p-p-p-p-r-p-p-p-r-p-p-p-p-p-p-p-p-p-pOk©‘^oa3nuk©'V'^n©®®©®»^o©oT^©n(o®<DP-'^TUkcouk'^^o)®o<o

0000 © (3k r- p- 00 p- 00 00 Uk Ok C7) 00 00 00 00 00 00 CO 00 00 (33 (33 03 c^ 00 00 p- 00 <o 03 CO 00 00 CO 00 00

r^p* p- P- p- p- p- p- p- p- p- p- p- p- r- p- c^ C^ P- c^ p- p- p- p- P- p- p- r- p- p00 Ok © OJ n *T Uk (O p- 00 cn © ^4 (U Ok © v4 ru n C7> © (U 00 Ok © ^4 cu n C7> © ^4 'T Uk <0 r- © © 0 w< •'^4 ^4 cu ru OJ cu n c^ n n n •<r Uk Uk Uk Uk Uk U3 <0 n n n n

niru ru fU fU nj cu CU CU cu fU (U cu cu cu (U cu ru cu cu cu cu ru (U ru cu cu cu cu ru cu ru ru ru cu ru cu cu

^4 ^4 cu cu cu cu cu cu cu cu cu cu ru cu cu cu cu cu cu cu cu cu cu cu cu cu

I

I

I

I
99

00 (A <X) 0<900 00 00 <i3 CX) 00000000 ^ 00> 0000000)® 00> OOOC^rnOO

U)(0 nn

cntn

no U) U) ncn

u) in

<nn

men

n <n T in rn n

intx)

men ^ o <sofijmo <s <soo ® o ®<s <s <sooooomooo> oooocu <s» ooT-* o ®

nici

(o<n

UMD

t^ n- r-co

iO ^o

in in

iOiO

CD in

r- r- ru o

r^ c^

o» o» (0(0

ooo>'<HoootoaoO '<-tLnoooooooooooo) oocx)'^ oo^ooooooooo

(U 00

in in

(O (O

t^ r-

(X)

(0(0

ID in

(0(0

in in r- n- fUO] r- r- o <9

r-r>- oocnoooio '^^ oo^o <n o o o o ^ ^ <s oon* r* r^ ocooo) 0 ^'70)ooook o ^

IDIO T'T'T in (JD in

<n<n m m m m m m

ininin m-^cn in^r-^ inin^ n*

m m m mmm mmm mmen m

90000 ^ 00> 00) 90000000000000000 ^ 0 (0 n](00000 l000

inr^m cor- to

n* r- r- co co co m ^ m ® o o> r- r- c^r- U3 r- 00 <s 0000k 0> 00000000000000000 <s 0000 ^<0 '^ 00 ^ 0'^00

(ucoin cn (o CO r-r- r- co co co ^ m o 00 c7> m

cot^co r- ® oo '^ in ® r»(7> r^<sajinooo ®<s)®® ooor^'rcoor- cor-® nj *Tti3 ® in <3)TOoo

n

- mn- ®oo m m m

m m m mmen mmm mcnm ® o ® (xjoinj aiojoi ®

m m m mmm mmm mmm m

®®®'7 ® ru ^ cn ® co ® o ®®®®® ooo ®®® 'T ®® n

"'v ® o> Oico ®®®'^® n- inCOn* TOCO CD o> ininin inn-in t t

OOOOC7) coinco inmco m

ininn- in in in ininin ininin co ® ojocD ®® om ® oo (7>'^®®®®®®®®®^®'T ® inooin ®® cnaj ® oo ® co®m

T ID T- in to in in in in in in ^ C7»

'<r in n- cor-® ® CO C7) cocoto <on-in m

'r'Tin to in in ininin ininin co oor- coooa3 ajaj '^ ru (nmm ®®®®®®®® oor- r- ooinmcu '^ comnjinc7)(7)® r'Lnm

(nmmmmmmmmmmm mcnmmmmmmmcnmncnrnmmmcn

®®in®®aicor-ca®(7>®®®®®®®®®o®®coa)oo®®n*co'T®a»in®ino)C7»

C7>®®coinLf)r-inc7)CT>oonj n'lninTrucncncncunjojcn

03 C»-^—« ojmcDr-(onj ®®®’maj'TTH ajajcnmTTTmm 'rT 'T 'r 'Tm 'TTm'T

•^ cD 'r ®® om ® ruo '^ C7)®®® o ®®®® C7>® mT -»-« cocomtor- c7)®®® m ® Ln ®

(T^ ootO '^'Tcom 'T 'r —

<

cs ®

n''^ TTmrnmmcu(ncnm -~< C7) C7i ® mnjrn ® rnc7)—•-^-^ nj ^ r- in-H

mcxjrum '^ TTTmm 'Tm ^'T '^'r'^'T

<or-oooooocaoor-cococ7>ooa>-^0)aioococx5cor-r-r-r-cor-CDa)CDa)CDa)cocDcocococD

mmmmmmfnmfnmmtnfn^fncnfnrnrnfnrnrnmrnrnromrnonfnmmmrommrnm mmncnmmmrnmmmnmmmmcnmmnmmmmmmncncnmmmmmmmmm

®cor-^cotoT®rnfn<o<o®toc7>'^®in»-«<o®®(7)(iJ'^^®tofUO)--'r-®®fn®<o®

oooooor-r^oor-oooor-r-r-cor^r«*r-oQr-cor-cococor^r-co'»r(or-r-cor-r-oor-cor-rr-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-r^r-r-r-c^r-r-r-r-r-r-r-r-r-r-r-

^»^mcijOfn^aj®fUT'®njo®(Oinco®ooro'v®--'coco®m®-^®®'v--*coLnm®

oooaoooor-ooooajoor-r-oor-r-cor-oor-oor-r-ncor-r-r-cococoooi^caoor-r-r-r-oo

r-r-r-r-r-r-r-r-f^r-r-r^r-r-r-r-r-r-r-r-r-r-r-r-r-r-r^r-r-r-r-r^t^t^r-r-r-rtnT’ LncoTLncor- ajm ^ intor- cocTicor- cocDrucoTin —

<

njm 'Tintor- oocT>®-^ rufn '^ '^'rT'^inininintotototO(o<oco<or^r-r-r-r-r-r-r-cocococQoooooococQ05C7>C7)C7>c7> furuainjnjfuajrurunjruruaiajrunjajfunjnjnjrunjainjfuajajajfufucunjnjrunjruaj

*-* -»-i nj ru fu nj fu t\i
KO

<u^oooiLn^or^c^oo<ii(iioo®r~oO'<^^oo(j3'«^ooooooooo
oo

Ln tn r-r- c^t'- -m 'T -rio

no no no on on no on

«*tu)00(x]ooo(uooooirtu)0onoo<90)'^ooo>ooooooo90osoo

U) <a 'T'T in^r lo in m in 't-h ld t*

fs-fw u) in rr *r lo lo r*-r- UJ to cunoo'^i/>oonooonrtioO'<^ooO'<Hoo^oO'^oooooooooooo

cun n IB -ri-r id ldo no 0003 r-cv UJU5 lO'T 1010 r-p- r-<o cxj to c»oooc^<ooor-c^o>omr^p-om'.-»(uooocun©o>t^(uono»^ooooooo


O'T' u)u)U9 r^p-r- c^p-r« O’^t T-xin

n n non non non non non non non

ooooo'T—toajnooaj(uo>oco*^-*-«oir)oooonor-OTOUDOoooo®oo

-TW OOOOCTI O'^LO 00 P- n- UJ LD 0» O T LD O P- P- (D 00 <0

p-r^ u)<jo<i) u>irtif> U)U)U) c^p-p- p-p-p- p-cDQO inLftui

U>0>003C;>OOOP-0'^0(X)<-iOOOOOO(7kOOO'TOOOOOOOOOC7)0000<DOOO

p-oo(D tAinu) inujn coldp- u)co*x cuoolo torupP-p- U)U)(X) LDU)U) LDLDU) P- P- P- P- P- <iJ<J0 U) U) LO P-00'*-«nJTOP-000)OCOP-<DO<i3000iOTCUnO’T’0)0000'^<S>0000000

non lOLoin. lointn ooo fu-«Hfu inioLO nn non non non non non non non

O^OC0nu>®'TC0T^O'^'VlDO00U3LDOC0OwO000)OOOOOOOOOOOOO

no n-t*'T n CD r-p->«-» p-oop- cd 't- oooo loocd

LO <o to to to ^ n n- n n -T- lo ld un lo ud to toioto t t

ooooooooo(uonjO)Lnou)to<^0'^ou)<sp>oo<soLoojoonT(S>oo<sooooo

ocn LDOLO njT^o tooru ldloo ooo co^ai nj

CO to CO CO CO 'r'T'T rn t 't- lo lo lo <o co co lococo ^ ^

O'VoiO'rp-cop-p-coootop-LDcunnj'rcocnp-ooLnconcjDnnnnoooooooo

<»H<r-*nnnnL0LnL0LnL0LnL0Ln-*-'^^^^-r-»^^ajnjfua3toLnL0L0 nnnnnnnnnnnnnnnnnnnnnnnnnnnnnn

®o>p-cO'«-MS<s-^(7>»^n(o<scoo'^o>oi®(7)oo-»^nooco-^p-ooruoooo®o<so

ui(UO»U)000)OO^LDnoooop-OLnajnoocoruin'TP-’rioo(Ucoi/>(U TTnLOLOLO-^cu-f-taj-ri^^cunnnajnnnn'T'T'r'Tcuairuni

intop*coocD'-<ru«-<oc7iocoop-ooLna)t^cDO^cotO'^iococoLnn®®ooo<so®

OOOnjP-nOJP-TTCOOOO'VOTP-n-^-^LOCD^'^fU'i^COCDO-r-tLOnj ''rioTioio-«-»^’^T-ifUT-*^^nnnnnajnnT'T'Tnnjnjnjcu

ooootooooo(7iooai)0>-<HG>CD o)'o> oo<soc>o>'^-<-«oo»-*6j'^TLon'^^T'^n'»-tnn

nnnnnnnnn'vnnnn'T’rT''vnn'^T'»r'^T''V'r'^'^T‘VT'V'T'^'^'r'^ nnnnnnnnnrnnnnnnnnnnnnn non nnnnnnnnnnnnn

ooT®^cooooooLn(Ucocu»^noooO’^<S'Tnrurur^oocoruo®®'^cno3Tooo<s

oocop-cooop-oocococor-p-p-oor^oop-p-oonoocoooaop-p-p-oop-oooop-r^cop-p-oooj

p-p-p-p-p-p-p-p-r^p-r^p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-p-pcu®>^too)tooinoconjLOOoooa>noiOOCDno(?)oocoio'voo><soop-»-»'TOP-Oi

00 CO P- P~ CO p- p- CO p- p^ p- CO CO p- p- 00 p- 00 CO p- p- 00 p- p- p- p- p- 00 P- p- CO CO tn p- 00 P“

p- p- p- P- P* P- p- p- p- p- p- p- p- p- p- p- p- p- p- p^ p- p^ p- p- p- P- p- p* p- p- p- p- p- p- iOtO p- CO CD nj n LO co p- 00 C7> 
 OJ n LO CO p- 00 CD o ru n '«r lO CO p- 00 CD <D ^4 03

O) cn C7» CD O) O o <s O o <s <s o <D ^4 ^-4 ^4 ^4 ^4 ^4 nj nj ru nj OJ CU tu 03 ru ru n n n

(U fU OJ (U CU n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n

cuajojaicuajnjajajrunjcuajtucuajcucufutunjnjnjfufuajcufunni
101

TABLE VII

Data for sequence A and sequence B heat treatments used to determine

C curves for 2219-T37* in this report. The range between the

solutionizing temperature (535°C) and 118®C was divided into 35 equal

intervals, h’rst given is a list of the bracketing temperatures.

Next, sample numbers are given followed, on the same line, by the

Rockwell B hardness, the conductivity in % lACS, the yield strength

(0.2S offset) in ksi, the ultimate tensile strength in ksi, the

% elongation and tJie % reduction in area, respectively. For each

sample the following four lines give a list of times, in seconds,

spent betVMen each of the temperatures listed, respectively. For

sequence A alloys the cooling cycle from the solutionizing temperature

was performed by a direct transfer from the solutionizing furnace to

a salt bath and then to an ice water quench. For sequence B alloys

a quench into ice water from the solutionizing temperature was followed by an immediate transfer to a salt bath at elevated temperature

and then by anotiier ice water quench.
102

TEnP RANGES

10 53S .0 523.1

10 416.1 404.2

10 297.2 285.3

06 178.3 166.4

511.2

392.3

273.4

154.6

499.3

380.4

261.6

142.7

487.4

368.6

249.7

130.8

475.6

356.7

237.8

118.9

463.7

344.3

225.9

451.8

332.9

214.0

439.9

321.0

202.1

428.0

309.1

190.2

SEQUENCE A

11 76.4 34.3 52.6 64.8 10.8 17.6

.2 «1 .1 .2 .2 .2 .3 .4 .3 .3

.4 .4 .6 1 . 1.8 27.6 .058 .058 .058 .058

.058 .058 .058 .058 .058 .058 .058 .058 .058 .058

.058 .058 .058 .058 .058

12 76.0 34.2 53.2 65.5 11.2 17.6

.2 .1 .1 .2 .2 .2 .3 .4 .3 .3

.4 .4 .6 1.0 1.8 27.6 .058 .058 .058 .058

.058 .058 .058 .058 .058 .058 .058 .058 .058 .058

.058 .058 .058 .058 .058

15 72.3 34.9 49.6 61.9 13.7 18.3

.1 .1 .1 .1 .2 .2 .2 .2 .2 .4

.4 .6 1.0 1.4 4.8 53.8 .03 .03 .02 .03

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03 * 16 69.5 35.4 47.8 61.6 15.4 19.2

.1 .1 .1 .1 .2 .2 .2 .2 .2 .4

.4 .6 1.0 1.4 4.8 53.8 .03 .03 .03 .03

.03 .03 .03 .03 ,03 .03 .03 .03 .03 ,03

.03 .03 .03 .03 .03

19 59.8 36.6 42.8 54.1 14.9 25.2

.2 .2 .2 ,2 .2 .3 .3 .3 .4 .5

.5 .6 .9 3.0 7.0 110.4 .0263 .0263 .0263 .0263

.026 .026 .026 .026 .026 .026 .026 .026 .026 .026

.026 .026 .026 .026 .026

20 64.3 35.9 45.9 58.4 13.9 20.0

.2 .2 .2 .2 .2 .3 .3 .3 .4 .5

.5 .6 .9 3.0 7.0 110.4 .026 .026 .026 .026

.026 .026 .026 .026 .026 .026 .026 .026 .026 .026

.026 .026 .026 .026 .026

23 47.1 37.9 35.1 47.5 15.7 21.3

,2 .2 .2 .3 .2 .3 .3 .4 .4 .5

.5 .6 1 . 2 . 17 . 279.2 .3 .3 .3 .3

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .1 .04 .06

24 44.0 37.7 35.7 47.5 13.9 23.4

.2 .2 .2 .3 .2 .3 .3 .4 .4 .5

.5 .6 1.0 2.0 17.0 279,2 .03 .03 0.3 .03

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .1 .04 ,06

31 76.5 34.1 54.1 67.3 10.8 19.3

1.2

.2 .1 .14 .16 .2 .2 .2 .2 .2

.32 .28 .34 .28 .4 .4 .6 1.0 1.4 10.6

40.8

.033 .033 .033 .033 .033 .033 .033 .033 .033

.033 .033 .033 .1 .1
I 103

32

3S

38

27

28

71

72

79

se

95

96

76.4 33.8 54.5 67.4 9.1 16.1

1.2 .2 .1 .14 .16 .2 .2 .2 .2 .2

.32 .28 .34 .28 .4 .4 .6 1.0 1.4 10.6

40.8 .033 .033 .033 .033 .033 .033 .033 .033

.033 .033 .033 .1 .1

75.9 33.6 54.3 68.0 9.7 19.3

.1 .1 .1 .1 .2 .2 .1 .2 .2 .2

.2 .2 .2 .3 .4 .4 .5 .8 1.2 3.0

51.4 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .08 .12

75.8 33.8 53.9 67.6 8.9 14.3

.1 .1 .1 .1 .2 .2 .1 .2 .2 .2

.2 .2 .2 .3 .4 .4 .5 .8 1.2 3.0

51.4 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .08 .12

77.3 33.3 54.8 68.7 10.8 12.2

.8 .3 .12 .18 .1 .2 .12 .16 .2 .2

.3 .26 .34 .4 .4 .6 1 . 1.2 3.4 9.2

.034 .034 .034 .034 .034 .034 .034 .034 .034

.034 .034 .034 .1 .1

78.4 33.0 56.1 70.1 8.7 12.4

.8 .3 .12 .18 .1 .2 .12 .16 .2 .2

.3 .26 .34 .4 .4 .6 1.0 1.2 3.4 3.2

.034 .034 .034 .034 .034 .034 .034 .034 .034

034 .034 .034 . 1 .1

72 .3 34 .7 51.2 63 . 7 12 .5 19 .6

6 . 8 1 . 1 . 1.2 3.2 24 .

4

.02 .02 .02

02 .02 . 02 .02 . 02 .02 .02 . 02 .02 . 02

02 .02 .02 .02 .02 .02 .02 .02 .02 .02

02 .02 . 02 .02 .02

73 .0 33 .9 51.7 64 . 8 8 .2 19 .3

6 . 3 1 . 1 . 1.2 3.2 24 .

4

.02 .02 .02

02 .02 . 02 .02 .02 .02 .02 . 02 .02 . 02

02 .02 . 02 .02 .02 .02 .02 . 02 .02 . 02

02 .02 . 02 .02 .02

74 .1 34 49.4 62 . 8 10 .9 15 .4

4 . 2 .2 . 1 .1 . 1 .1 .2 .2 .2

4 . 2 .4 . O .7 1 .3 1 .2 1 .4 2 . 4 1 09.4

• 1A .•VWW 036 .•V^wW 036 .036 •VWQ .0 36 .aVwW 036 . 036 . 036; .036

.036 .036 .036 .036 .03

72.2 34.4 51.0 64.4 11.7 12.7

.4 .2 .2 .1 .1 .1 .1 .2 .2 .2

.4 .2 .4 .6 .7 1.3 1.3 1.4 2.4 109.4

.1 .036 .036 .036 .036 .036 .036 .036 .036 . .036 .036 .036 .036 .036

72.2 34.3 51 . 1 64 .0 13.3 28.0

.5 . 6 .6 .6 .6 . 4 ,8 1.0 1.2 1.6

4.0 6.4 .02 .02 .02 ,.02 .02 ..02 ,.02 .02

.02 .02 ,.02 .02 .02 ..02 .02 ..02 ..02 .02

.02 .02 ,.02 .02 .02

72.8 33.9 53 . 0 66 .6 13.1 16.3

.5 .>6 .6 • O . 6 . 4 ,8 1.0 < 2 1.6

4.0 6.4 . 32 . 3 2 .02 .02 .02 .02 .02 . 02

,02 .02 .02 . 02 .02 .02 .02 .02 .02 . 02

.02 .02 . 02 .02 .02

.033

.034

.034

036

036
104

83 67.1 35.1 47.0 59.2 13.2 25.2

.3 . 3 .4 .6 .6 .8 1.0 1 . 4 1.6 3.10

6.0 20.0 .02 .02 .02 .02 .02 .02 .02 .02

.02 .02 .02 .02 .02 .02 .02 .02 .02 .02

.02 .02 .02 .02 .02

84 69.0 35.7 48.6 60.8 10.3 21.5

.3 . a .4 .2 ,6 .2 1.0 1 . 4 1.6 3 . 0

8.0 20.0 .02 .02 .02 *02. .02 .02 .02 .02

0.03 .02 .02 *03 .03 *03, .02 .02 .02 .02

.02 *02 *02 .02 *02

87 61.2 36.2 44.1 55.7 12.0 20.6

.4 . 4 *6 .6 *8 *8 1.0 1 * 2 2.0 2 . 4

14.4 54.4 *02 .02 *02 *02 *02 .02 .02 .02

0.02 0.02 .02 ,02 .02 .02 .02 *02 .02 *02

0.02! 0 . 02 . 02 .02 * 02

88 60.9 36.0 42.8 54.1 12.4 25.3

.4 . 4 .6 .6 .8 .8 1.0 1 . 2 2.0 2 . 4

14,4 54.4 .02 .02 .02 .02 .02 .02 .02 .02

0.02 0*02 *02 .02 *02 .02 *02 .02 .02 .02

0.02 0.02 .02 .02 .02

111 56.6 36.9 41.3 51.6 13.1 29.0

.22 .5 .7 .8 1.4 2.2 15 . 6 108 .4 .03 .03

,03 .03 .03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 .03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 .03 .03 .03

112 56.1 36.8 41.8 52.6 12.4 16.9

.22 .5 .7 .8 1.4 2.2 15 . 6 108 .4 .03 .03

.03 ,03 .03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 .03 .03 .03 .03 .03 . 03 .03 .03

,03 * 03 * 03 . 03 * 03

107 63.6 35.7 46.3 57.3 12.8 21.7

.32 .5 .7 .8 1.4 2.2 15 ..6 45 . 0 . 03 . 03

.03 *03 *03 *03 .03 .03 .03 . 03 .03 .03

,03 .03 .03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 .03 .03 .03

108 67.5 35.9 46.8 57.7 14.0 18.8

.22 .5 ,7 .8 1.4 2.2 15 ,.6 45 . 0 ,,03 . 03

.03 .03 .03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 .03 .03 .03 .03 .03 . 03 .03 .03

.03 * 03 * 03 * 03 * 03

103 73.5 33.7 54.4 67.7 9.9 13.5

.2 .2 .1 .1 .1 .1 .1 .2 .6

.6 .3 .3 .6 .6 2 . 00. 03 .03 . 03 .03

.03 .03 .03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 .03 .03 .03

104 77.3 33.9 53.9 67.1 9.2 15.9

.2 .2 .1 .1 .1 .1 .1 .2 .6 .4

.6 .3 .3 .6 .6 2.0 .03 .03 .03 .03

.03 .03 *03 .03 .03 .03 .03 .,03 .03 .03

.03 .03 .03 .03 .03

91 78.1 33.7 54.5 67.4 9.4 19.4

.1 *3 *1 .1 .1 .2 .5 .7 .5 .1

3.1 .025 .025 .025 .025 .025 .025 .025 .025

.035 .035 .035 .035 .035 .035 .035 .035 .035

,035 .035 .035 .035 .035

035

. 035
93

115

116

119

120

123

12-4

127

123

131

132

135

105

77.5 33.3 53.7 66.7 11.3 16.8

.1 .3 .1 .1 .1 .2 .5 .7 .5 .1

2.1

.025 .025 .025 .025 .025 .025 .025 .025 .025

.025 .025 .025 .025 .025 .025 ,025 .025 .025 .025

.025 .025 .025 .025 .025

73.2 33.7 54.1 67.6 7.7 19.6

.1 .1 .1 .1 .1 .1 .1 .1 .2 .2

.2 .2 .2 .3 .6 1.5 .03 .03 .03 .03

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03

78.8 33.2 54.7 68.4 9.5 14.7

.1 .1 .1 .1 .1 .1 .1 .1 .2 .2

.2 .2 .2 .3 .6 1.5 .03 .03 .03 .03

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03

76.6 32.9 54.4 68.4 8.7 11.9

.1 .04 .1 .1 .2 .2 .1 .2 .3 .3

.2 .6 2.5 .018 .018 .018 .018 .018 .018 .018

.018 .013 .013 .018 .018 .018 .018 .018 .018 .018

.018 .018 .018 .018 .013

78.5 33.1 55.0 67.3 10.1 19.2

.1 .04 .1 .1 .2 .2 .1 .2 .3 .3

.2 .6 2.5 .018 .018 .018 .013 .018 .018 .013

.018 .018 .018 .013 .013 .018 .018 .018 .018 .018

,018 .018 .018 .013 .013

79.3 33.0 54.5 68.4 10.2 12.1

.2 .1 .1 .1 .1 .1 .1 .1 .1 .2

.2 .2 .2 .2 .2 .3 .3 .3 .4 .4

03 .03 .03

1.2

1.6 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03

79.3

33.4 54.4 68.4 9.1 12.5

.2 .1 .1 .1 .1 .1 .1 .1 .1 .2

.2 .2 .2 .2 .2 .3 .3 .3 .4 .4

1.2

1.6 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03

78.0 33.1 55.2 68.7 7.5 12.4

.2 .1 .1 .1 .1 .1 .1 .1 .1 .2

.2 .2 .2 .2 .2 .3 .3 .3 .4 .4

.4 .4 .4 .8 1 . 1 . 2.2 4.4 .057 .057

.057 .057 .057 .057 .057

79.1 33.3 54.7 68.3 9.5 11.5

,2 . X .1 .1 .1 .1 .1 .2

.2 .2 .2 .2 .2 .3 .3 .3 .4 .4

.4 .4 .4 .8 1 . 1 . 2.2 4.4 .057

.057 .057 .057 .057 .057

67.9 34.5 51.2 64.6 11.3 14.0

057

3 .5 .8 1.1 2 .4 2.2 2.2 5.6 21.6 .023

023 .023 .023 .023 .023 .023 .023 .023 .023 .023

023 .023 .023 .023 .023 .023 .023 .023 .023 .023

023 .023 .023 .023 .023

.9 34.0 50.9 163.5 7.8 15.1

3 .5 .8 1.1 2 .4 2.2 2.2 5.6 21.6 .023

023 .023 .023 .023 .023 .023 .023 .023 .023 .023

023 .023 .023 .023 .023 .023 .023 .023 .023 .023

023_^^023 .023 .023 .023

.0 35.6 45.5 56.3 12.3 24.7

2 .2 .4 .6 2 . l.S 2 .S 13.3 44.4 . 015

015 .015 .015 .015 .015 .015 .015 .015 .015 .015

0 l 3 .015 .015 .015 .015 .015 .015 .015 .015 .015

015 .015 .015 .015 .015
106

136 63.7 35.8 44.5 55.5 13.6 35.0

.2 .2 .4 .6 2. 1.8 2.8 13.8 44.4 .015

.015 .015 .015 . 015 .015 .015 .015 . 015 . 015 .015

.015 .015 .015 . 015 .015 .015 .015 . 015 . 015 .015

.015 .015 .015 . 015 .015

139 59.7 35.8 44. t 54 A L 3.5 15.0

.1 .1 .6 .6 1. 1.2 1.8 6.4 1 12.. .038

.038 .038 .038 . 038 .038 .038 .038 . 038 . 038 .038

.038 .038 .038 . 038 .038 .038 .038 . 038 . 038 .038

.038 .038 .038 . 038 .038

140 59.5 36.3 42. 0 52 .8 :16.

2

21.4

.1 . 1 .6 • 6 1. 1 .2 :L .8 6 .4 112.0 .038

.038 .038 .038 . 038 .038 .038 .038 . 038 . 038 .038

.038 .038 .038 . 038 .038 .038 .038 . 038 . 038 .038

.038 .038 .038 . 038 .038

143 78.6 33.2 55. 8 69 .8 9.9 17.8

.1 . 03 .03 . 03 . 03 .03 . 03 . 03 . 03 . 03

.03 .03 . 03 .03 .03 .03 .03 . 03 .03 .03

• 03 .03 . 03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 . 03 .03 .03

144 77.2 33.0 55. 1 69 .0 8.7 17.6

0.1 .03 . 03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 . 03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 . 03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 . 03 .03 .03

147 76.8 33.8 53. 9 67 .4 9.8 16.1

.1 . 4 .5 .6 1. 1,. 1 .9 4. 4 9.4 .03

.03 .03 . 03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 . 03 .03 .03 .03 .03 . 03 .03 .03

.03 .03 . 03 .03 .03

148 76.2 33.5 53. 7 67'.6 9.8 cn .

• .1 . 4 .5 .6 1. 1.. 1 .9 4. 4 9.4 .03

03 .03 .03 .03 ..03

03 .03 .03 .03 ,.03

03 .03 .03 .03 ..03

.9 37.9 37. 6 47..1

22 .5 ..7 .8 1.4 2.

.017 .017 .107 .107 .017 .017 .017 .017 .017

.017 .017 .017 .017 .017 .017 .017 .017 .017

.017 .017 .017 .017 .017

152 50 .

S

37.2 37.9 48.0 12.6 26.9

.017

.017

22 ..5 .7 .8 1. 4 2.2 59.6 242. 0 .8 .017

017 .017 .017 .017 .017 .017 .017 .017 .017 .017

017 .017 .017 .017 .017 .017 .017 .017 .017 .017

017 .017 .017 .017 .017

155 47.7 37.3 35.3 45.4 15.7 35.7

3 ,.7 .7 .9 1. 3 .9 601.7 .03

03 .03 .03 .03 .03 .03 .03

03 .03 .03 .03 .03 .03 .03

03 .03 .03 .03 .03

.1 38.1 35. 8 -T 5 .5 15.3 29.6

3 ,,7 .7 .9 1. 3 .9 601.7 .03

03 .03 ..03 .03 .03 .03 .03

03 .03 ,.03 .03 .03 .03 .03

03 .03 ..03 .03 .03

.03 I

.03

03 .03

03 .03

I

I

I

I
107

159 78.0 32.4 56 . 3 70 .3 11.0 20.7

.4 . 9 1.8 3 . 0 55 .7 .02 .02 .102 . 02 . 02

.02 .02 . 02 .02 .02 .02 .02 .02 .02 .02

.02 ,02 . 02 .02 .02 .02 .02 .02 .02 .02

.02 .02 . 02 .02 .02

160 77.1 33.3 53 . 8 66 .3 14.1 26.3

.4 .,9 1.8 3 . 0 55 .7 .02 .02 . 02 . 02 . 02

.02 .02 . 02 .02 .02 .02 .02 .02 .02 .02

• 02 .02 . 02 .02 .02 .02 .02 .02 .02 .02

.02 .02 , 02 .02 .02

163 75.5 33.8 52 . 2 64 .4 9.3 19.6

.9 4.1 598 . \ .04 .04 .04 .04 .04 .04 .04

.04 .04 . 04 .04 .04 .04 .04 .04 .04 .04

.04 .04 . 04 .04 .04 .04 .04 .04 .04 .04

.04 .04 . 04 ,04 .04

164 73.7 33.3 54 ,.1 66 .3 9.7 15.0

.9 4.1 598.4 .04 .04 .04 .04 .04 .04 .04

.04 .04 . 04 .04 .04 .04 .04 .04 .04 .04

.04 .04 . 04 .04 .04 .04 .04 .04 .04 .04

.04 .04 . 04 .04 .04

167 78.1 33.5 55 .. 1 68 .7 0.0 14.7

.4 ,.1 .1 .1 .1 . 1 . 1 .1 .1 . 2

.1 .3 .2 .3 .3 . 4 . 4 .4 .5 . 3

.1 :1.4 2 ..8 6.4 . 227 .227 .227 .227 . 227

.227 .227 .227 .227 .227

168 78.3 32.4 54.8 68.3 10.4 16.5

.4 .1 .1 .1 .1 .1 .1 .1 .1 .2

.1 .3 .2 .3 .2 .4 .4 .4 .5 .8

.1 1.4 2.8 6.4 . 22? .227 .227

.227 .227 .227 .227 .227

171 76.5 33.2 54.3 67.4 11.7 21.0

.2 .1 .1 .1 .2 .3 .1 .3 .2 .3

.4 .3 .4 .4 .5 .7 .7 .8 1.0 1 2.6 5.0 16.5 .25 .25 .25 .25

.25 .25 .25 .25 .25

77.7 33.5 56.4 70.0 7.2 8.0

.2 .1 .1 .1 .2 .3 .1 .3 .2 .3

.4 .3 .4 .4 .5 .7 .7

2.6 5.0 16.5 .25 .25

.25 .25 .25 .25 .25

78.5 33.6 53.5 67.1 11

.1 .1 .1 .1 .2 .2 .1

.2 .2 .3 .3 .4 .4 .4

172

7

25

8 1.0 1.7

25 .25 .25

227

227 .227 .227

.25 .25

.25 .25

175

176

179

3 17.6

2 .2 .2

4 .6 .8

1.0 1.8 2.8 6.4 43.4 .045 .045 .045 ,045 .045

.045 .045 .045 .345 .045

77.9 33.5 54.7 68.6 10.4 14.8

.1 .1 .1 .1 .2 .2 .1 .2 .2 .2

.2 .2 .3 .3 .4 »4 ,4 ,4 ,s ,3

1 . 1.8 2.8 6.4 43.4 .045 .045

.045 .045 .045 .045 .045

76.5 33.7 53.2 66.4 9.3 21.5

.1 .1 .1 .1 .2 .2 .1 .1 .2 .2

.1 .2 .j .2 .4 «4 ,4 ,4 ,Q ,s

1 . 1.8 2.3 6.4 281.3 .15 .15

.15 .15 .15 .15 .15

.045 .045 ,045

15 .15 .15
ise 76,0 33,7 sa ,6 66.0 9.8 14.1

.1 ,1 .1 .1

.1 .2 .3 .2

1 . 1.8 2.8 6

,2 .2 .1 .1

.4 .4 .4 .4

.4 281.8 .15

.2 .2

.6 .8

.15 .15 .15 .15

183

.15 .15 ,15

75.9 34.1 49 , .15 .15

6 63.5 11.9 13.5

.1 ,1 .1 .1 1 .2 .3 .3

.1 .2 .1 .2

.5 ,4 .5 ,6

.2 .2

.7 .9

1.1 1.6 2.8 3.0 588.4 .03 .03 .03 .03 .03

184

. 03 . 03 . 03

73.5 33.9 51 .

.03 .03

8 64.8 9.0 16.5

.1 .1 .1 .1

.1 .2 *3 .3

1.1 1.6 2.8

*1 .2 .1 .2 *2 *2

3 ? 0

* 588? 4 *? 03*^.03 .03 .03 .03

264

.03 .03 .03

66.5 35.9

.03 .03

48.0 60.5 9.0 16.3

.2 * 2 .3 .3

• 8 1 * 3.0 56

•2 *3 .3 .3

.6 ,04 .04 . .4 .5

04 ,04 .04 . 04

.04 .04 .04 .04 .04 .04 .04 .04 .04 .04

265

.04 .04 .04

66.4 35.9

.04 .04

48,0 60,5 9.0 16.3

*2 .2 .3 *3

.8 1 . 3 . 56

*2 *3 *3 .3

.6 * 04 . 04 . .4 ,5

04 .04 .04 . 04

.04 .04 .04 .04 .04 .04 .04 .04 .04 .04

256

.04 .04 .04

76.9 34.3

.04 .04

54 .

4

68 «

6

7.9 7,7

.1 .1 .2 .1

1 . 2.4 11.8

.2 .2 * 3 * 4

* 02 * 02 * 02

.4 .6

.02 .02 .02 .02 • .02 *02 .02 * 02 * 02 * 02 .02 *02 *02 .02

257

*02 *02 .02

74.9 34.1

.02 .02

54.8 68.7 8.0 14.0

.1 .1 .2 .1

1 . 2.4 11.8

.2 .2 .3 .4

,02 .02 .02

.4 .6

! 02*.02 .02 .02

*02 *02 *02 * 02 .02 . 02 .02 .02 .02 .02

291

.02 .02 .02

70.5 35.2

.02 .02

48.8 62.4 9.0 16.3

298

207

208

.2 .2 .2 .1 .2 .2 .1 .1 .2 .2

.2 .2 .1 .2 .2 .3 .3 .4 *4 .8

1.6 1.2 2.0 3670 . .06 .06 .06 .06 .06 .06

.06 .06 .06 *06 .06

69.4 34.9 49.3 62.4 8.8 13.4

.2 .2 .2 .1 *2 .2 .1 .1 .2 .2

.2 .2 .1 .2 .2 .3 .3 .4 .4 .8

1.6 1.2 2.0 3670 . .06 .06 .06 .06 .06 .06

.06 *06 *06 .06 .06

77.3 33.7 54.1 67.4 12.1 19.0

.6 1 . 1 . 1.6 5.4 7,6 .09 .09 .09 .09

.09 .09 .09 .09 .09 .09 .09 .09 .09 .09

.09 .09 .09 .09 .09 .09 .09 .09 .09 .09

.09 .09 .09 .09 .09

77.8 33 .. 6 55.0 68 ..9 1. 2.7 16 , 8

.6 1 . 1 . 1.6 5.4 7.6 .09 .09 .09 .09

.09 .09 .09 .'09 .09 .09 .89 .89 .09

.09 .09 .09 .09 .09 .09 .09 .09 .09

.09 .09 .09 .09 .09
109

387 73.3 34.4 50.3 63.3 - 8.0 13.8

.1 .1 .3 .1 .1 *1 *2 .1 .1 .1

.1 .3 .2 .2 .1 .3 .3 .3 .4 .6

.6 1.2 4.0 1790.5 .04 .04 .04 .04 .04 .04

.04 .04 .04 .04 .04

388 73.3 34.4 49.2 61.1 7.6 21.7

.1 .1 .2 .1 .1 .1 .2 .1 .1 .1

.1 .2 .3 .2 .1 .3 .3 .3 .4 .6

.6 1.2 4.0 1790.5 .04 .04 .04 .04 .04 .04

.04 .04 .04 .04 .04

SEQUEMCe B

339 75.1 34 . 4 51 . 8 65 .5 10 .9 17.0

.046 .046 • 046 • 046 .046 « 046 .046 . 046 ,.046 .046

.046 .046 9 .25 1 . 65 0.94 0 .75 0.45 0 .45 ,,045 0.35

0 . 4 S 0.25 0 .45 0 .25 0.25 0 .15 0.25 0 .25 0.15 0.15

0.15 0.15 0 .25 0 .15 0.25

330 74.7 34 . 2 52 . 8 64 .8 9 .5 16.5

0.045 .045 .045 .045 .045 .045 .045 .045 .045 .045

.046 .046 9 .25 1 . 65 .94 .75 . 45 .45 .45 -.35

.45 . 25 . 45 .25 .25 .15 .25 . 25 .15 .15

.15 . 15 . 25 .15 .15

333 68.

8

36 . 0 46 . 7 58 .6 9 .7 22.5

.026 .026 026 • 026 .026 026 ^ 026 ^^ 026 .026 .026

.026 .026 27.3 1 . 65 1.15 • 55 .55 .55 .45 .45

.35 .45 .35 .35 .25 .25 .25 .25 .15 .25

.15 .25 .25 .15 .35

239 66.8 36 . 4 47.1 59 .5 9.3 15.5

.026 .026 .026 .026 . 026 . 026 ,026 .026 . 026 .026

.026 . 026 27 .75 :1 . 65 l.li5 .55 . 55 . 55 .45 .45

.35 .. 45 . 35 .35 . 25 .25 .25 . 25 .15 .25

.15 ,.25 . 25 .15 .35

203 56.4 37 . 4 38.4 43 .4 13.3 28.1

.02 ..02 . 02 .02 .02 .02 .02 . 02 109 .75 1 . 653

1.05 .86 .65 . 65 .45 .69 1.09 .99 . 99 .79

.69 .79 . 59 .59 .59 . 59 .59 . 49 .59 .49

.29 . c 9 . 19 .19 . 19

304 52.9 37 . 3 37.8 47 .7 15.9 27.5

.02 .02 . 02 .02 .02 .02 .02 . 02 109 .75 1 . 65

1.05 .85 .65 .65 .45 .69 1.05 .99 . 99 .79

.69 .79 . 59 .59 .59 .59 .49 . 59 .49 .49

.29 .29 . 19 . IS .19

195 53.6 37 . 2 38.1 48 .7 14.0 26.0

.03 . 0 j . 03 .03 . 1 .

1 1 50.1 70.0 1.44

1.53 .73 .531 .63 .33 .43 .43 .63 .6 3 • 63

.53 .53 . 73 .73 .93 1.23 2.23 3.43 .03 . 03

.03 .03 . 03 .03 .03

196 53.6 37 .. 2 38.1 48 .7 14.0 26.0

.03 .03 , . 03 . 1 . 1 . 1 50.1 70 . 1 . 44

1.53 .73 . 53i .63 . 33 .43 .43 .63 .63 . 63

.53 .53 ..73 . 73 .93 1.23 2.23! 9.43 .03 .03

.03 .03 .,03 .03 .03
39S

296

299

300

303

304

307

308

242

243

260

no

74.7 33. 9 53.5 67. 1 10.2 16.4

.03 .0*3 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 *03 *03 .03 670. 07 3 .67 1.47 .97 .77 .77

.57 .57 .57 .67 .57

75.0 33. 9 55.4 67. 3 8.8 16.5

.03 *03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

• 03 .03 .03 .03 670. 07 3 .67 1.47 .97 .77 .77

.57 .57 .57 .67 .57

68.6 36 .2 48.2 62 .3 7.0 10.1

.02 .02 .02 .02 *02 .02 .02 .02 .02 .02

.02 .02 .02 .02 .02 .02 .02 .02 .02 .02

.02 *02 .02 *02 1930 .06 2.96 1.16 * 86 . 66 .46

.45 .45 .45 .55 .55

66.9 35 .9 47.1 62 .1 9.6 11.5

*.02 .02 .02 .02 .02 .02 .02 .02 .02 .02

.02 *02 .02 .02 .02 .02 .02 .02 .02 .02

.02 .02 .02 .02 1930 .06 2.96 1.16 * 86 * 66 .46

*45 .45 .45 .55 *55

54 .

6

37 .4 38.91 49 .6 14.2 20.8

*03 .03 .03 .03 *03 .03 .03 88.26 2. 26 1. 86

2*26 1.66 1 .06 . 36 . 66 * 46 . 46 .46 . 46 .36

.36 *26 *26 .26 .26 .16 .26 * 16 * 16 .16

.16 .26 .16 .26 .26.

55.0 37’.6 38.6 49. 3 14.9 25.3

.03 *03 .03 .03 .03 .03 .03 88.26 2. 26 1. 86

2 4 26 I466 1«06 4S6 *66 *46 *46 *46 *46 *36

.36 *26 *26 *26 *26 .16 .26 *16 .16 .16

*16 *26 *16 *26 *26

59*7 37.4 39.8 49.6 12.1 27.6

.03 .03 .03' .03 . 03 .03 .03 117. 66 1 .96

.66 *46 .46 .46 .56 .66 .56 .46 .36 .36

.36 .26 .26 ,25 .26 . 16 .16 .16 .16 .16

.16 .16 .16 .16 .16

•

li) 37 .3 39.6 50 .5 12.1 23 .7

.03 .03 .03 .03 .03 .03 .03 117. 66 1 .96

.66 .46 .46 .46 .56 .66 .56 .46 .36 .36

.36 *26 .26 .26 * 26 .16 .16 .16 .16 .16

.16 .16 . 16 .16 .16

53.7 37 *1 38.3 52 .6 10.0 20 .1

36

36

06

49 .49

06

*06 *06 *06 .06 *06 .06 .06 .06 .06

.06 .06 79.30 6.50 1.70 .90 .79 .59

*4 *3 *3 *3 *3 .3 *3 .3 *3 *3

* 3 * 3 * 3 .3 * 3

55.4 37.6 40.3 52.3 11.8 15.5

*06 .06 *06 *06 .06 *06 *06 *06 *06

•06 *06 72.3 6.5 1*7 .9 .8 *6 *5 .5

*4 *3 *3 *3 .3 *3 *3 .3 *3 *3

*3 *3 *3 *3 *3

66.4 36.3 46.4 58.1 10.9 13.7

.03 .03 .03 .03 .03 .03 .03 .03 25.97 1.87

1.27 .97 .57 .57 .47 .37 .37 .37 .27 .27

.27 .17 .27 .17 .17 .17 .17 .17 .17 .16

.27 .17 .17 .27 .17
261 66.4 36 .3 46.4 58 . 1 10.9 13.7

.03 . 03 .03 .03 . 03 . 03 .03 .03 25.97 1.87

1.27 .97 .57 .47 .47 .37 .37 .37 .27 .27

.27 . 17 .27 .17 . 17 . 17 .17 .17 .17 . 17

.27 .17 .17 .27 .17

251 71.4 34 .9 50.8 63 . 1 13.0 21.3

.03 . 03 .03 .03 . 03 . 03 .03 .03 11.68 l .(38

1.08 .68 .43 ,48 .38 .38 .48 .28 .28 .18

.28 . 13 .28 .18 . 18 . 18 ,18 .18 .18 . IS

.18 . 18 .18 .13 . 13

252 71.9 35 .0 49.4 61 . 6 14.5 27.3

.03 . 03 .03 .03 . 03 . 03 .03 .03 11.68 l.i3 S

1.08 .63 .48 .48 .33 .38 .48 .28 .23 .18

.28 . IS .28 .18 . 18 . IS .13 .18 .18 . 18

.18 . 18 .18 .18 . 18

274 66.0 35.9 48.0 59 .9 12.2 19.1

.03 .03 .03 .03 .03 .03 20.78 3.68 1 .38 .98

.58 . 48 .48 .38 . 38 . 38 .23 .28 .28 . 28

.18 . 28 .13 .28 . 28 . 18 .18 .18 .18 . 28

.18 . 18 .18 .18 . 18

275 65.9 35 .8 47.6 59 . 2 11.7 23.1

.03 . 03 .03 .03 . 03 . 03 20.78 3.68 1 . 38 .98

.58 . 48 .48 .38 . 38 . 38 .28 .28 .28 . 28

.18 . 28 .18 .28 . 28 . 18 .18 .18 .13 . 18

.18 . 18 .13 .18 . IS

283 76.9 34 .0 55.1 69 . 0 7.9 10.5

0.3 . 03 .03 .03 . 03 . 03 . 03 .03 .03 * 03

.03 . 03 .03 .03 . 03 . 03 22.58 7.28 1 .68 1.08

.78 . 48 .58 .48 . 53 . 58 • 38 . 28 . 28 . 28

.28 . 18 .23 .28 . 28

284 75.4 33 .9 55.2 68 . 9 6.8 12.0

.03 . 03

'* .03 .03 . 03 . 03 .03 .03 .03 . 03

.03 . 03 .03 .03 . 03 . 03 22.58 7.28 1 . 68 1.08

.78 .48 .58! .48 .53 .551 .33 .28 .28 .28

.28 . 18 .28 .28 . 23

236 71.4 35 .1 48.0 60 ,,9 8.6 13.9

,04 ,.04 .04 .04 ,,04 .,04 .04 .04 .04 . 04

.04 ,,04 ,04 .04 ,,04 ..04 53.38 3.03 1 . 59 .88

.88 <,78 .53 .48 ..98 jL .18 1.08 1.08 .78 . 78

.58 .,48 .38 .38 ..28

237 70.2 35:.3 49.3 62 .. 6 7.5 13.7

.04 ..04 ,04 . 04 .04 ,.04 .04 ,04 . 04 ,.04

.04 ..04 .04 . 04 .04 .04 53.38 3.08 1 .. 59 .38

.88 .78 .58 .48 .98 ;L .18 1.08 1.08 .1rs . 78

.58 .48 .38 .33 .28

245 62.9 3 £i • 5 43 .

3

56 .7 8.9 13.1

.04 .04 .04 .04 .04 .04 .04 .04 .04 , 04

.04 .04 .04 .04 .04 .04 117.79 3.09 ;L . 2 S1 1.09

.59 .59 .49 .49 .49 .79 .79 . 69 .49 .39

.39 .29 .29 .19 .29

246 63.0 36.8 43.3 57 . 1 S.S 20.4

.a-4 .04 .04 .04 .04 .04 .04 .04 .04 .04

.04 ,04 .04 .04 .04 . 0.4 117.79 3.09 1.59

.99 .99 .49 .49 .49 .79 .79 .69 ,49 .39

•39 . E9 .29 .19 .29

1 .09
112

215 79.6 33 .3 57.0 70 . 3 14.5 17 . 5

• 03 .03 .03i .03 .03 .03 .03 .03 .03 .03

• 03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

• 03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

• 03 .03 .03 .03 . 03

216 78.7 33 .4 56.6 69 . 9 11 . 4- 17 . 4

.03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

• 03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

.03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

.03 .03 .03 .03 . 03

311 75.0 31 .9 54.3 67 . 9 8.6 12 . 6

.03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

• 03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

54.6 2.16 .96 .76I .56 .46 .36i .36i .26; .36

.26 .26 . 26 .26 . 26

312 78.5 32 .5 54.2 67 . 7 9.3 14 . 5

.03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

.03 .03 .03 .03 . 03 . 03 .03 . 03 . 03 . 03

54.6 2.16 .96 .76 .56i .46 .36; .36i .26; .26

.26 .26 .26 .26 . 26

315 75.4 33 .5 52.8 65 . 7 8.7 13 . 4

.03 .03 .03 .03 ..03 . 03 .03 . 03 . 03 . 03

.03 .03 .03 .03 ..03 . 03 .03 . 03 ..03 ..03

115 . 28 4 .48 1.58 .98 .78; .68 .48 .78 .48

.28 .28 .28 .28 <.28

316 74.7 34 .5 52.2 66 .,0 8.2 13 .,5

.03 .03 .03 .03 <,03 ..03 .03 ..03 ..03 .,03

.03 .03 .03 .03 ..03 ..03 .03 ,.03 ,.03 ,.03

115 . 28 4 .48 1.58 .98 .73 .68 .48 .78 .48

.28 .28 .28 .28 ..28

319 67.91 34 .9 49.5 62 ..8 7.9 IS ,.0

.03 .03 .03 .03 .03 ..03 .03 ,.03 ..03 ..03

.03 .03 .03 .03 .03 ,.03 .03 ,.03 ,.03 ,.03

232 . 57 6 .27 1.57 .87 .77 .57 .47 .47 .37

.57 .87 .57 .47 .27

320 66 .

4

35 .5 50.2 S3 ..3 8.4 13 ..6

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

.03 .03 .03 .03 .03 .03 .03 .03 .03 .03

232 . 57 6:.27 1.57 .87 .77 .57 .47 .47 .37

.57 .87 .57 .47 .27

4 S

.48

.37

.37
113

TABLE VIII

C curve parameters for aluminum elloy 22I9-T87*

Prooert'/ Seouence “o sec cal /mol °K

%

cal /mol

,1

— (U > • w

•

Hardness, HRB A 79.0 46.0 .26x10"^° 320 900 32,000 2.2

Yield Strength

(0.22 offset)

ksi

A 55.3 35.4 .78x10'^° 320 900 32,000 1.5

j

Tensile Strength

ksi A 69.0 45.1 .79x10*^'^ 320 900 32,000 1.7

Conductivity

% lACS

A 33.2 37.7 .59x10"^° 320 900 32,000 0.4

Hardness, HRB 3 80.6 53.6 .23x10“' 200 900 25,000 1 9

1 Yield Strengtn

(0.22 offset)

ksi

3 56.5 35.7 .37x10“^ 200 900 25,000

1 1.4

1

1

1

Tensile Strength

ksi = 69.5 45.4 .43x10*' 200 900 25,000

! 1.3

Conductivity

2 lACS

3 32.3 37.4 .17x10*^ 200

1

1 900 1 25,000

1 O.A
114^

TABLE IX

Parameters obtained for C curve fits ta hardness data, for varying

values of (Kg was chosen: and kept fixed while the other

parameters v/ere adjusted ta obtair a minimum least squares deviation)^

SnHRB

*^0 HRB

%

Sec

1^3 cal/mole

•^4 K cal/mole

est.

std^

dev..

79,Z 46.0 240 892 28,000 2.5

79.0 44.9 .43x10"® 320 905 30,000 2.2

79.0 46.0 .78x10"''° 320 900 32,000 2.2

78.5 41J .56x

10*”^'^ 335 886 35,000 2.2

78.J 39.3: .12x10"” 335 881 37,000 2.2

78.d 40.4 .23x10"” 595 921 40,000 2.2

78. T 40.0 .48x10'’''^ 570 919 42,000 2.3
115

Table X, Specimens Examined by Means

. of Electron Microscopy

Condition

As cast 10:1 reduction ingot

As-received T851

532®C-75min ->• Quenched 0®C

532®C-75min ^Quenched 0®C Age 177®C-18h

532°C-75min -* Quenched 0°C -> stretched 2 1/4%

Reprocessed T851

532‘’C-75min ^ 350°C-15s -* Quenched o

o o

As-received T87*

535°C-75min - 450°C-15s -» Quenched 0°C

535°C-75min ^ 450^C-30s Quenched 0°C

536®C-75min - 400°C-30s Quenched O^C

535°C-75min ^ 400°C-60s Quenched o°c

535®C-75min ^ AOO^^C-oOs Quenched 0®C Stretched 5% Age 172^C-16h

537®C-75min - 400°C-15s -* Quenched 0°C

537®C-75min ^ 400°C-15s Quenched 0°C - Stretched 5% Age 172^C-16h

538®C-75min ^ 450'^C-60s Quenched 0®C

538®C-75min - 450‘’C-60s - Quenched 0®C - Stretched 5% -» Age 172^C-16h

Reprocessed T87*

535®C-75min - 450°C-15s Quenched 0°C

535®C-75min - 450^C-300s ^Quenched ^Stretched 5 % ^ Age 172^C-16h

536'*C-75min ^ Quenched 0°C

535®C-75min Quenched O^C - 400°C-30s - Quenched 0®C -^Stretched 5% ^

Age 172^C-16h

535®C-75min - Quenched 0°C - 400®C-30s - Quenched 0®C
116

249 535°C-75min Quenched 0®C -»•

250 535°C-75min Quenched 0®C ->•

Age 172®C-16h

253 535®C-75min Quenched 0®C

322 537®C-75min -*• Quenched 0®C

Age 172°C-16h

2219 F temper

°C-15s Quenched 0°C

®C-30s - Quenched 0®C Stretched 5%

°C-30s -** Quenched 0°C

®C-60s Quenched 0®C Stretched 5%

450'

400

450

450

t Initial material T851 1 1/2“ plate
117

TABLE XI

Hardness of Several Sequence A and B specimens After

Completing the T87* Temper.

t Hardness after

Specimen Quench Treatment T87* Treatme'

#197 (Fig. 73a) quenched directly to 0®C 79.0jj3.96 HRB

#93 (Fig. 73b) sequence A, 400‘’C-15s 73.2+1.1

#81 (Fig. 73c) sequence A, 400°C-30s 67.3+1.8

#85 (Fig. 73d) sequence A, 400°C-60s 60.5j:1.2

#69 (Fig. 74 a&b) sequence A, 450'’C-30s 72.4jj3.55

#249 (Fig. 79a) sequence B, 450‘’C-15s 72.0+,!.

2

#253 (Fig. 79b) sequence B. 450°C-30s 65.6j:1.4

#232 (Fig. 79c) sequence B, 400°C-30s 67.2+0.73

'These hardness values were obtained from companion specimens given the

same quench treatments as those indicated in the left hand column.
TABLE XII

List of data obtained on round robin samples.

Column 1

:

Lab number

Column 2: Sample heat treatment code

1 = sequence A (5% stretch)

2 = sequence B (5% stretch)

3 = sequence A (no stretch)

4 = sequence A (2-1/2% stretch)

Column 3; Sample number

Column 4: Yield strength in MPa (0.2% offset) as measured at NBS

Column 5: Ultimate tensile strength in MPa as measured at NBS

Columns 6-11: Hardness measurements, Rockwell B

Columns 12-14; Conductivity measurements, % lACS
119

us(ooonjoo<-i«-io30Drur^oo^air-o>aja)0)ooo'ra3ajoou)cooo<so®oou)

t^^cT^'T^T’nconTn^ix)u>aj-Hncnnjcxj-^vuo^coajTC7)C7)tflO^X)'^'^nj

•^LO(*ifn-«r'TncDnmr)fn(nr?r-tnwr-(ncOLOLn'^^r-na)<D'Tu>mr>cn'^ nnnnnnnnnnnnnnnnnnnnnnnnnnnnnmnnnnnn

<n o»'*-«nnnv^O)LD(\jr-cfla3C7)00o<»-i'TO>ru^oococDr^ruoou)'m)<S)0®m®®

Tr“innLD-^'Tmconrj'VLnLDC^»-»cnt\jo>r)oa'rH'T(jQ(7)C7)aiT®a)U)<scDaino

T^u>nfnT*majnmnmmnr-r»'r'^c^mcx)if)LomTr-nr-a3T-ir»inDrT^ nnnnnnnnnnnnrnnnnnnnnr^nnnnnncnnnnnnnnn

CM

u>r-a>oa)oo'^(X)tx)^'^c7)anD<xjc7>Ln-^njoa3C7»o3ajnjoor-ajn®ooooLn®

cnu>Ti/)'^-«-i^-^LDajnaiai’rvnj(T»'r®nr-®TCDCor-fuajCD
Lnr-oo
ai'r

'r-^Lftr)m’<r'T“mtDncnn(nmfnrMnTrLf)r-ncDir)un(T)vr-ncijr^^^t/>nm-«r nrnnnfnfnnnnnf*innnnnnnnnnnnfnnnnnnnnnnnnn

u)o>c7)ooLnu)aioo'70'^^o)^ajQ)U)ajnjo<so3(i}oooooc7><*>«cur-coLnaj

t^>»-«LDOOOOn”rC7»®C7>0>CD(7>C^OOaJOOLf>'^(Dr-LDt^r-L/)fU'TCX3CX3tDI^rUU)OiO'f

r-r-CDr-r-r-r-r-(flr-r-c^r^r^r^LOi^r^c^Ln(^tDcocDcot^Lr)r-i/)ur)(^r>-cDr-oor>-

(VJ»^i/i-*-iOLftfn<ui^<®najooir)cuu)®0(n'voo'SO«soajfuoir>fU’^y)fUP-ooj

p-l 03njLncncarun-cocnc7>ooc7)cocoooc7ic7)cn'^Lnu3'^a5r-Ln'^'^oon''^(j3ajr-cxjai'Tr-r^u3(^r-c^r>-r^Lftt^r-c^(^-c^^-TC^r^r>-Lnr^(i3CDcococ^Lf)r-LOLf>r-c^cor-r^f^

ooc\j®ooo<sir>(DOC7)r-a3>i-»a3njr-<s-^^oor-<scoooco-*-'r-a)i/)oonjr^naj-«-*

o>| t^-«Hcooooon'^oooooooooc7>oocooc7)co>»^n‘r-vc7^r«-'ro'rr^<DLnconjr^oocoLn r-r-cor^t^r-r-r^<Dr^r-r-r-r“r^LDr-(^r^Lnc^tD(uu}coi^Lor-LnLnr^r^<ijr-o-^-

coLni/>'7
<scom<scaLn'^'^oO'^OLOLnoO'<-«oo>o(^OLor^o(^-^oo'700ix>oru

aol CM^tooooofnfnoia)0)0>cDo»r-r-'^oo<ij'»-ttor-Lno)r^Ln'^LDC^a)cDJi)nLf)®®'T^

f^r^O)(v.C^(v.[M(s.u^js.Is_[M(N.c>wjv.u^c>_(v_js.l/,fv.y3<xJ<i)CDr-Urtr^lOLDC^r-<i3000QrrocoT»-tn
cr>cooM3'^Lncx3-^(7)<S)'>^''^Ln-^LnO'^<scoru'TajLDr-ruru'^cx3Ln

r^l r^nLncor^m'^cocT)OQ)ooc7>p-oO'^fMCD-<cor-cx)oor^LO®cDr^i/)LnLnLncDC7JO>^

r-r^cor-r-r>-rMr>.moor^tM[s-f^(v-LOfs.[v.(>^LOjv_<j3<^<^^jfs.LO(N.y^ij^rs.(\.(jO(v.tv.rv.

^(iJOioajaiT’oO'^'^a)'»-'a)'^LnLf><S'^CT)rufuo)<soocfl®oooo<sO'^r^ruT’Lnoo

U) CM LO 00 00 OJ 00 00 00 a> 00 00 r- 4 CO CO o LO 4 CO 4 OJ LO CO CO CO LO 03 CO cn O) 4

r- CO r- r- 0- LO 00 0- r- LD o- r- r- LO o- CO CO CO CO LO LO LO 0- r- LO r- r- r1^)1 o CO Lf> r> «s 
 n lO C7» o OJ *r cr» CO «4 o o> CO m n OJ C7) ^4 00 ^4 44 o- O o CO cn n 
 o T nj 00 00 o o CO LO 0- 0- r- o- CD Lf) r) T OJ CO r- o ^4 ^4 00 m 4 CO 
 <S> 4 OJ 00 00 o 
 n T 
 T 'T n 'T T "T T 'T n T n 4 4 4 cn 4 cn 4 <s» 4 4 cn 4 Cd o

00 CO l/> 'T r- CO cn m m LD n CO CO in ^4 CO <s OJ ® LO (7> r~ 4 O 00 CO 4 r- <D o »=S’l n m o 00 
 lO r- 00 r- r- 0- 00 r- CO CO m r- o- OJ n n n cn CO r- 
 <S> n m O 00 O o rn n n m o <s m cn OJ m n n n n Cl OJ n cn cn OJ n cn n cn OJ cn OJ cn <s O m cn n cn O <3>

rol U) T 00 CO 00 o OJ o CO OJ 00 'T 00 OJ CO OJ cn 44 LO CTt cn cn CO 03 o n 4 LO 4 00 CO 4 CO

o OJ n n r- o ^4 ^4 OJ LO 0- r- o o OJ cn •4 LO LO CO 0- o- CO OJ OJ o m 4 03 ro n

O <s <9 o o o ^4 ^4 ^4 ^4 ^4 ^4 OJ OJ OJ OJ OJ OJ 03 OJ 03 OJ 03 n m n n o o <S) o o o

«M| •^4 ^4 ^4 ^4 ^4 ^4 ^4 ^4 •4 ^4 ^4 OJ ^4 03 03 03 44 OJ CU cn ^4 03 ru 03 03 4 ^4 ^4 44 ^4

'—

1

•^4 ^4 ^4 ^4 ^4 ^4 *^4 ^4 ^4 •^4 4 ^4 ^4 ^4 44 ^4 ^4 44 ^4 ^4 ^4 ^4 ^4 44 ^4 44 OJ ru 03 03 03 OJ

k
120

OOOOOOOOOOOOOOLDOOIDOOOO^OOOOOOOOOOOOOOO

®'-^canjnLD<OLDO'TCutx)niLnp-(^maiO)COLft-^ooj<flOC7ir^r**cono'^cn«jiocQuo

•ruDnmmnnnr^mT-LDr^rncDLnLnm-^r-mr-^-'^LOLnnm-^'^^comcnmnn ddnnnc^nnnnfnnnnnDnnnnnnnnnnmnnnnnnDnnnoi

oiDtnooooo^ooooooooooooooooooooooooooooo

u>ajr^aj*-«”Tr^<ULOTnj^OLO<j3 'T'ru3 ooaLn^-^^tn»Hr-o3 Lf>u3 cotx)Lon'^<DC^c^

^ruDnnnntnmc^n'^tnr-ntoiriLn'm'r-nr^t^'TLnmncTV'^majcnmrjnn cncnmcnnnocincnnoKnncnnc^nnnoicnnnmnnncnnmcnnnncnmn

^OLOOOU^OLOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

^^r-n(unju)r^u)'^'VLn<^Lnt-t’<r'^oo'rr“LDr-—•ciiTaiOLncflCDcoooLnnco'T<i3 LD 'rrKDnnnmnnr-m'rmr-TCDLnLn'^Tr^nr-c^'^Lnconn'^TrMijnrKDmm c»)nnncocnoincnnrTnnnnromnc^nnnnnrnnncT)nnnr7,nc^nnnn

tnoiooiDOO'-^n-.^T'vanfl'^'^OJCOLOOajLn'.-tooooj'^Lncoc^oir^LnO'^'-^irjcou)—

•

im»aj'^aj»^oooom-^r-cftLncaLnoiooco'TCD(7><DC^u)aio3 C»coLnu3 '-^aj»^®<so)0

r-r^<i3cor^cocooor-LDoor^<joix)r^cDtflU)cof^LDr-tnLnr^t^a3r^r-r^c^cotoooa3tx3c^oo

oiu) 0) 0)-HCoocx3 coLf>cDtooincoLno>o><iJcor-'^oa3 r*-ajLD'-*aifU'r-toa)U)cosO-^o

u>o>t-*oo) 0)ocDoo^c7)r*-cocDcoLno'ii^y3 njLf)oooor-r-cnr-oo<i3 monj'r^«-t
'^'^

r-r-<Dcor-r“Cor-r-LDr“r-<Du^c^<ocotfltflr^Lor-inu^r-c^<flcooor^r-oo(i3 a3 ooooooaj

iftUifnco<^concnfun30oocoajoo>*-ioO'»-icn-r^oo)ooo>'^®^C7)Lnrur^o>®'^njocnQD

tDO>«s>®o>oc7iooo3 '«risp-^i/)OQi/>a»r-tx)n(Door^ti3 r^cn(7)OOcoc^c7)nj'^®'^o-^

r-r^u3 cxjr^coc^t^r-u^car-r-i/)r-<ococDU)r-Lnr-Lninr-r^<ucooor“C^r-tx)cocoo3 cx3 co ooooin*-^o>r^o»n-»-i*Tnj-vcor-o>o>coo>cuoo)onajo-^'^r^r^OLf)njLDLOU>r)-rioi

ino>^oo)oa>c7icoTor^cnuDcofno>coiDfULf)cxjcoo)oococ7)C7>«smcflono®^oa>

r-D-cooor-cor-r-r-Locor-r^Lor-uj<DU3 mr'Lnr^u^u^r^^-cDr^oor^c^c!Ocflo3 cooooor^

cna3 tnu)-•(T>aJ(nfnooo’^^-c^'r-lC7)^-a)(D^-® 0)nJT-•alC7)LDcoaJ^U'^u^n-H®^-OLn

tDo<s<so)<s®OTcO'r-ior-njcDO)'^ooooLnrncooocooor^”TC7)o®cotDOT'^-i-<'«-i-»-*T-i

r-oou3 oor-cooor-r-if)cor-r-inr-tQU3 m<i)r-Lor-LnLnr-r^cDCocar-^-oau)cooocococo

®co-«-*t^Looaiajc7>a>o>mt^ajooir>oormoaj®Lnr-'»Hr^oci3 -*-»LDmoo)-«-**-*oino>tn

U>0>^Oa>OC7>CX3 r- CD o- -w-4 CO 0- d CD CO CO d CO CO 0- CD LD CD o o CO LD CD X ru o CD CD r-r-yjoor-oor-r- c^ LD r- r- U1 r- CO CO CO CO r- ID 0- U) cn r^ CO 00 00 r^ CO CO 00 00 r- ntncDonj^'TOi (S3 O CD co d d cu CD CO xH 0- o o CO U1 d o o d LD CD tu ^ H X CD ^iDinr^o-r^r-tjD LO d 0^ T ru CO 
 00 d X co o 
 X ru 00 00 (S o X CD LO r- r- CO 'TTm'^T'T'^'r 'T d '*r 'T T d X X X X d X d X <s o X X d X o 
 X X d X X X X X

inTt^r-dDOicnn ID d CO LO CO o ru <s CD Oi 0- X (S o 00 CO X o LD X r^ D- CO CD d d

u>r»ojt^c^r^cx)r- CD CO O- CO d 0- 0- ru d d d d co <s o d d 00 o 
 LD 00 CO nDojnnmnn 01 ru d d d cu d d d d ru d cu d o <s d d d d 
 o d d cu d d d d d

oojooonjooo'T CO fU CO nj ID ID CD d d CO o ru (S d X U1 X CO CO X 00 O tu o CO ru 00 o X

(r^®-.-»»-»cuLr>r-r- 0- o 
 ru d X ID ID CO CD o x^ cu ru 
 ru d d r- <S) cu U) D- r- O »-* -r-i -r-i ru ru ru CU cu cu cu ru ru cu cu d d d d o O o <s» o x^ X—

4

•«—» 1 1 1 1 1 1 1 1 ru ^ cu CU cu (U ru d (U (U cu cu X T-i x«^ x^ x4 xH

(XJ fu (\j nj o] ni ru nj fU nj fUfU fU cu ru (U oi cu cu tu ru cu cu cu d d d d d d d d d d d d d d

I

I

I

I

I

I
121

^9 ^D

cDiOT^-co-Hajm-'rLncsO'-iLncDocD'^ajr-LnLonjcocoLnLnLnLnr-aDC^LDLn-^r-'^^

r»r-n^’rr>-mtounLn'<r*»r<i3fna)f^^i/>conn'TTn<ij(nnncnfnmr^n“^u^r-'^to focnncnmrHncocnmcnnnnntntncncinncnronnrjcncncnnmcnnnnrjnm

r-TLD<D-^'^c7)'^mcooc7)OLnc7)oa)ajoor^'ru>r-(UO'mLOC^o>a)<flLOLou)u3'^to

cot^m'Tu^r^ntOLDLn'T-'rconcor-^LninmrvT^nr-rnnrnfncnmr-rvvLnf^^co ncnfnnnnfnncnmcnncnoinrntnnnnoinnnnnrnnnfnnnnnc^nnc^ ^ O O O <S O O <9 O O <9 O <9 9 O <9 9 O 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9

^(nTtocuajoorutOLnruc7>^L099cDrufU'T’(DcoLO'^c'-r^u3vcD<-oco<D'roo'Tr-9^

nr'-Pi^Lnr-rocoLnLD'^'^cDrjr-r-TLfttDrnn’^'^ncDnnnnmrjr^fn'^Lor-'T^iJ

fn n n n n n n-n nnnnnnnnnnnnnnnnnmrnnnnnnnnnnnn

99i/^najLninmr-9u>9LOLDajT^fU9(ur-c^nr^9LOC^ruru9'^(n(^(nnLoc^'r^to

9O)*^r^r-C7)cnca99r-Tr-C7»-»^O)Lf)mu)r-cx)ini/)O>ruoicn9O>o)O>-^O)r^r^ix)C0C0

coLoooc>-r-Lnr^mf^r^cx>t^tDr^<ouDt^r^<i3r^c^r“C^r-ujc^r^oor-r-r-Lnr-t^tDiot^uj

9ajaiaj99'^9LnLnLn9Lnr-Ln9>^^»H00Lou>r-r-r^r-o»aiaiTP“ncou5ajr-a)-^

9u»'-^r-'^t^cnoo9'-^<i)Lf)t^a)a)0>m-^c^^-cx3inLncD'^c7)C7)C7>o>a>03'^0)ci3'^iDf^(X>

ooirtoo^-r-unr-u3^-r-cDr^u)C^LOLDr^r“Cflr^r“r-c^r-tx)r^r“r~r-r^r~Lftr^r-r-LDr-cfl

cuoou)ir>9ajr-9LD9tnLn99-«^-»-»'^'v<r}C7>r-’«rfur“aj(DLnLoo)a]r-oiOcoo)fnc3>o»

9i/)9t^r>-c7)cor-9avr-'ra3'»-«-f-«a>tO'«-«<i)t^ootn<^cx)-^cr>c7)a)ooc7>oo-vcntorumf^Ln

ooir>oor^r-Lnr-cor^cDcor^tnoocoLf>r-r-(Dr^c^r^r^r^(i3r-r^c^r-f^c^i/)C^^-c^Lor^<ii

in 9 9 n in 9 in ru n- in in 9 nj tu 00 9 U) m to to 00 cn 00 ru ru 9 9 CO T ""T 00 cn roi in CD cn O) 00 9 cn to T- cn cn 9 m cn in 00 00 in cn 9 9 cn <n 00 00 cn cn P- r P- p- m

r^ incD r- r- in n- to r'- to to in in to r- p- to p- p- p- to CO 00 p- p- P- in p- p- in p>- to

.1 .5 .3 .3 9 cn in in to 00 r- in cn 9 00 00 rn to cn n to to cn cn T- cn 9 cn 00 00

a> Lf) —• cx) CO 00 r- 9 cn r- cn r- cn 9 in 03 c^ cn 00 in cn ^4 cn cn cn cn tn 00 ru cn to 03 to to

r- in 00 r- r- in r- to r- to to r- in to to p- to p- p- p- to p- p- p- c^ p- p- in p- p- P- in p- to

00 9 in n cn in cn in 9 ru in 9 9 9 cn 9 cn cn cn in (U cn P- ru to ru 00 ru in 00 to cn 00 00

CMX) O 00 in cn 00 00 9 00 r- cn 9 in ru in 00 00 T in cn 9 cn cn cn cn cn 00 cn 00 to m in 00 in

r- in 00 in r- to r- <o to r- in 00 in to p- c^ to p- P- p* p^ to p- p- p- p- p- in p- in to

to 9 C7> to fn rn ru cn 00 p- o 9 9 to in cn 9 9 m in cn 9 ru T cn to ^4 9 cn to cn cn ru

in m r- -r OJ to 9 CO n •V to 9 9 nj 00 00 9 O T (O in c^ to in m C^ ru to p- 9 m T 'T n ~r *T- 'T 'T cn T- n T 9 9 T- T cn T 9 9 T cn »r T 'T V 'T 'T m V T cn ”T in (nuo -» in <o 9 ru 9 in CT> T" 9 9 00 to 'T P- 9 9 in 7“ p- to cn cn cn in m to in to 9 to to r- <n n r- ru m m m cn 'O P- 9 9 m m 9 00 9 9 in 00 p- 00 p- to to p- to cn CU n ru m n m OJ n m m cn ru m ru m 9 9 cn m m n 9 9 m m cu cn cn m cn m in ru m m cn cu cn cn cooj to nj in in cn m rn to 9 ru 9 m T in 00 to •<r 00 9 ru 9 00 ru CO 9 'T CO ru to 03 in m cn

r- 9 9 OJ n •T in in to r- n- cn 9 ru ru 9 ru m rn p- 9 ru in p- p- 9 9 ru cn •>r in in

nj ru oj ru m ru ru ru ru ru ru cn cn cn n 9 9 9 9 9 9 9 ru ru cu ru 03 OJ cu 1 2 1 a OJ oi - ru ru m ru ru ru <u •«r - - Oi cu (U ru v>4 03

3 3 3 3 cn m cn m n n cn n cn cn cn cn T 'T “T* T T 'T T 'T 'T T T T 'T
122

O O <S O ® O O O O CD ® O LO O U) CD O O O O O O O O O O O O O O O O O O LD O O

coo)^o<oa)CTTfucxi»-icooojo>co^ooa3-ri«o»'r-»ooc^ooooooo)ooo>nnooo»u3

mii>^u^r-nr-c^’^Tir>rucijnnaKDnjnjcnnjnmr-njnn'r-r)i/^'«r'mTC^ncoco c’icnnnr7nnnnnndnmcnnnnnn(ndnnnncnncnnn(*in(^ndn(^

OOOcJoOOOOOOOLnOLDOOOOOLOLDOOOOOOOOOOOOOOOO

r-o>ajT-t<flD-nm^Lnocoo>®o)r->^ooLno3C7)oooa3cx3U3oooooo<s)nru«r^oooco

inir»-vLDc^nr-r-'^Trmnjru'vcnnj;Dajnja]ajncnr-njcn'^r^mLn'^i/)cn'«rr^tn<i5co nnnnnnnncnnnnnnoicnnnDnnnnnnnnnnnnnc^nnnncn

OOOOOOOO^OOOinOLDOOOOOOOLnOOOOLOOOOOOOOOOO U)OOTO><X)CO'<r'T®LO®COO>000>'^0)C7)COO^CnOtI3COmOOC^C7iOn-m<SOLnLO

iniD'^'rr-nr-r-’^'TLnnjru -^'^ru cDnjnjnjcn(najr^a]rv^r-nLn'«rir)r)'^r-fiJcoyj oincnnnnncnnnnnnntDnnnnfnmnnnnnncnnt^nnrnnmnc^tn

u>cno)cni/><Dnjotoou)ooou)U)OU)oou)LOOU)oou)ooLnLDLnu)ooou)Ln

oor-u>aj'^r^r-tDr^ajr^a30>LDLno>n3oiojoo»Oia>mor>-noocoLno)oor-mr-ococ^

ujtocor-Loc^LOLor^r^tDr^^-r-c^r-tDr-r^oof^r^r^LOCxjr-r-LDC^ujcDcxjcor-Lnr-LOLrt

o)oo'^c7>'^t^r>coooLr><su)Lnou)<DLnoLr)u)U)<SLnLnt/)Lnu)Lnoo<SLooLr)OOLn

C7)r-inajt^cDr^c^(Dnr^oco'TU)o>aj®o>o>c7>o>(7)^0)r-LOOocaujo>C7>t^cnco®cor»

Q3(Dior^ino-inLnr“r-u)cor-r-r“r^cocor^r-r-r^r-Lf)r“r^r^Lf>r-(D<D<DtDr^LnoouDm

OTr“OorT^moou>u>®Ln®oiDOin<su^u^o<SLnLDU)UDmLno<suiwou)oocn

cnootncDCDC7)co(DCD'»-*r^oocoLDU5C7)n3oo)C7)ooo)a>-vcor^LnoooocDC7)cnr^^LDOico«j ajcDtiMfiLor-LOLor^r^tor-c^r-r-i^iflcor^r^r^r-c^Loc^r-t^Lnc^ujcocflUJC^uit^LOio

r^nr>o(7)ru(i3ooooLnoLDOOooLOLOo®ooLr>i/>ooo<9<s<so<su)U)OLn

o»o>LOcucDO)r-coi/)mr>-0)0)'VTOti3®0)0)
o)C7)taocxjLnoicx3iDOC7)oo(rjr^oocfl uxD^r^Lor-iiiLor-iXDr-r-c^r-CQtocor-c'-oor'-c^Lncxjc^r^LnD-cDr-yjcDr-LnoodJtD

o^ooL()a]'Tooo>Lr>ou)ooLn<sLnu)OLninooLn<sinoooou)(SOO<soLDLnu)

o>comajr-cor-ooTnLf>cJio>'^cocnooo)C7)o®c7>ruo)oo'^coc7)a)ooor-nr>-cx3oor-

«juj«)r-Lnr-LDtor-c^u)r^r-^-c^i^(Uoor-c^oacor“Lor^c^r^Lnc^<Dr^u)ujr-uit^u5Ui

P'“<o<ocj)c^Lo<D(DLnif)LnLr>Lo<scnLDLDmooootr)oi/)Lr>ooLnifioo'SomO'SU5

coooift-r-iunr^ooco “T n Lf) cn 00 lO CD Oi O) ® ® ® C7> cn m at 0- cn cn CQ 00 rn (O o 00 cn «)<j3U)r-Lf)r^LDLn r- r- CO r- r- r- r- CO r- 00 00 00 0- in o- D- in CO CO CO CO r- U3 CO in in 1 O) 00 C'" o ® ® <J0 cn n ® ® n lO O) o 03 o> CO ® cn CO cn cn OJ tn 00 o- ® ®

^i-ioon'Tyjoo ru 00 00 ® ® CO CO r- 0- 0- 0- CO in cn T cu CD r- ® CO tn CO o ® ^TD'rn'roo T T n T ® ® T “T n T 'T n 'T T’ cn n* cn T n ® ®

1 cuoi/)0>t^'ro<s CX3 CO r- o ® LD CO Oi n n tn m CO CO in CO o cu ® in tn r- ® ®

1 tnnncncor^oo 1 cn n ® CO ® o LD 03 r- 00 CO CO 0- r- m ru m m m m CO o o

(nncunnjno® cn m m m ® ® m n OJ n n n cn n n ru cn cn cn 03 cn cn cn m cu cn ru tn o ®

n<*M0oajorn'v Lo n- 00 <o 00 ® OJ ® 00 03 00 ® 00 03 CD ru in in cn m tn CO o 03 o tn 'T- ujc^r^oo-^ajru o ro (TJ <n ® OJ U) r- r- ® ® OJ m cn in CO o- c^ tn o 03 03

(u cu oj c\3 n n n tn o o ® o ® ® ® 03 03 OJ 03 ru ru OJ ru OJ 03 OJ tn tn tn tn ^ fu r> oi oj 03 (u 'T <•-• -• ^4 (U cu 03 03 ru ^4 03 tn 03 tu tu tu

'T -r 'T 'T 'T -T 'T T l/> LO lO CO LO to lO in Lf) to lO LO in in in in in in in in in in in in in in in in in
Table XIII

Summary of measurements by five laboratories on thirty samples of 2219.

Column 1: sample number

Column 2: Yield strength {Q.Z% offset) in ksi (NBS measurement)

Column 3: Ultimate tensile strength in ksi (NBS measurement)

Column 4: Average of 30 Roclcwell B hardness measurements

(6 by each of 5 laboratories)

Column 5: Standard deviation of the 30 hardness measurements

Column 6: Average of 15 conductivity measurements in % lACS

(3 by each of 5 laboratories)

Column 7: Standard deviation of the 15 conductivity measurements
124

I

V

p

onooor)LDtDr-cDmLnnjooooLn-^ajocncoLoo>coo)nmr^r-mfUCD ajcunnajcucutnnjcuncucuajnnjncnaicumfucuntnaiLnaKUcu

uiOicncur-'t-in^rr-^io.^m^'^nmconjajOTr^'^'TinoO'i-'m

vo| ^ooujtncnncnmmnjnjcT^Ln'vnajmonr-ainLrjoir^^H'roo

WLD<nn'«r'vna)mnnnnmr-n'«rLn(^rnDimrjcn*^r-mr- rnnnnnnnnnnnnnnnncnnnncnnnmnrnnnrn

r-

(71

r-oir-’^(rJO'rooos®^o<Door->»-*co’v>»H-^'^ooconju)<\inno

in I f»i-.-iajo>o>'«-»OLf)ncor-otoo)C^(X)oca”^ui(a3fn(n(7JOioaj»^<jQui

wH- C\J

cDi/)cncn'^^r^mrumr-^ajLnrn^O'^^^r-^^(7i
oruajwn

cnooc7iO®ci3cnLD'TruLoc7>u3ajo-r^D-aicu®'^®^^cnr^'TOo®<a

•^1 cooj<x)0)(7)'TUioi-rHocr)(7>oi(7>(Mcnc7)t^(nr-oococ7)03corucoracoc^

t>-pw(X)r-r-r-t^r-(D(X)r-c^r-r-c^uir^r-c^uir-cfl(iHfl<Dr-ir)r-u>in

coooooooooj'T-^'-HTOir^O'^o^-i^iacDconocniK^ui^r-®®

ri'r-»uio ^iNnjoQ<xi{X)cxj(5no.co(X3ui'^cu(»03®c:n(xjcu(7)f^

ui u) CO in u) U3 m U3 CO m ui <13 (D ui ui ui U3 ui til m '<r (D

®r^-^-^oouinjcor-LD<33Ui"r-i(7)^Lr>Ln<onui'T^(3a^o3r-ruoo

oioo'Tco »H^^’<r'Ttnui’^ruco'^'^ooc7>^cooor-TOi(33'^

''T'H'ui ui u) 'T ui ui ui LD ui ui n ui in n ui 'T T T cn ^ tn 111

in'ToocD'^(30<snjoooa30Q(S'T(»aicoruin»^inoinn<o<sfUO(*i'^

»^'^njmnc^o»^'^njinc^c^r^o<sfun'H'inuicor^r-c;iO'»-‘(\inj ^^^^^^^^fuaicuajnjfUfunjfururtjncirKTi
125

Table XIV

Parameters obtained in least square fitting Equation (13) to the yield strength

vs. the conductivity of the 2219-T87* round robin samples as measured by each

of the five participating laboratories.

Lab.

No. ^0 ^2

Residual

Std. Dev.

ksi

1 -105.2 12.72 -0.2375 1.4

2 - 63.23 10.08 -0.1962 1.2

3 - 59.80 10.42 -0.2091 1.7

4 -119.0 13.24 -0.2405 1.1

5 -21.50 7.783 -0.1663 1.2
Table XV

Parameters obtained in least squares fitting Equation (19) to the yield strength

vs. the Rockwell B hardness of the 2219-T87* round robin samples as measured

by each of the five participating laboratories.

Lab.

No.

fi

Residual

Std. Dev.

ksi

1 27.43 -0.0785 0.005372 1.2

2 24.47 -0.0038 0.004773 1.1

3 31.92 -0.2750 0.006877

4 24.45 -0.0298 0.005176 1.0

5 27.21 -0.1290 0.005948 1.1
127

I

Figure 1 Measured average composition {vit.% copper) hardness (HRB)

and conductivity (%IACS) versus distance through (bottom

to top) an as-received 12.7 cm f5 inches) thick pl-=>te of

2219-T851 aluminum alloy (Reynolds Lot No. 7950777-01).

The dotted lines indicate location of top and bottom.
c 128 >
DISTANCE, cm

g . . easured yield stress, ultimate tensile stress, percent

elongation and reduction in area versus distance through

VDOttom^to too) an as-received 12.7 cm (5 inches) thick

sluniinum alloy (Reynolds Lot No.

/950777-0I )

.

%

R

A

and

%

Elongation
<-

18.78

130

a3ddoo % '®o

DISTANCE

IN

X-DIRECTION

,

cm

Figure

3.

Macrosegregation

profile,

average

copper

content

versus

distance

from

the

chill

face,

across

the

short

transverse

direction

of

a

semi-continuous

DC

cast

ingot

of

ccy'i

aluminum

alloy.

Ingot

is

from

the

Reynolds

McCook

plant.

It

is

idenitified

as

2219-13^02-98.
131

Figure 4

I

\ ' \i V A 1 ^ At 5 10 15 20 25 30-»***35 40 45 50

Wt. % Cu

Calculated solidification "path", dashed lines, shown on the

liquidus phase diagrams of the aluminum rich corner of Al-Cu-Mn,

Al-Cu-Fe and Al-Cu-Si systems. In (a), Mn remains in solution

until solidification is completed at the ternary eutectic point.

In (b), the solidification "path" intersects ihe eutectic trough

L-^ct-Al+Cu2FeAl 7 before solidification is completed at the ternary

eutectic point. In (c), the "path" intersects tne eutectic trough

L-^-A1 +Cu 2A1 before solidification is completed at tne ternary

eutectic L-c:-Al+Cu2Al^Si

.

I
J

</l

to o <c

u

(Us-

(Uc > •»- -o

(U -o <— •«- U. (Q <<U T3

<4-

C LJU

C

O ^ *o

<U E 0> 3

(Q

C 4-» T- C S

O) 3 O •—

&. <T3 <U I a. d

<u <4- > o n3 O -M O £=3

i- o O -s=

1/1 c0 •»- 01

(Ui_ <a

(U Ll. ^ IN 3

CJ

O) -M

S- too

Ofl»r- C <4- <(O I 0) d S T3 —1 O Tto O CQ

CO < N

<u

4-1 o c . _ 1 3

(/> O) -t-4 4J C_J >, CO IT3 (t3 -r co OJ O- U

Q.C <

(/I OJO <1> S- -f- -3 LU

4J *1— CM

CO (O r— 3 c a o o o CO -i- I CUI 3oI Cl-f- >><c

r— O) *3 S- I ea; GC Id d

r— *3

r o

CO

sO) ou

C(-o 3 3 CJ Q..C CO 4-O O

CO

a

>1 • o s- "n I— 3 3 O

U

r— "3 +-» 23 3

(d c o^+-» •1-3 3 ^ <d 3: 3 3 E 3 -i-> 3 CO (d ^ u (d C. s- JZ to = 3 2. 3 3 3 3: c 4-> 3 -2 3 ^ - 1- +J = ^ 4J CO 3 4-> CO 3

r— T- o O 33 < 3 Q--4-^

CO3

S.3

31
133

Figure 6. Typical SEM views of the as-cast microstructure of 2219

aluminum alloy, (a) Shows cored dendritics and interdendritic eutectic at lOOX. (b) Shows the interdendritic

eutectic at 400X.
134

Figure 7. Typical optical and SEN views of the interdendritic region of

as-cast microstructure of 2219 aluminum alloy, (a) Optical

view, Keller's etch, light phase is a-Al , gray phase CuAl 2 » dark phase Cu 2 FeAl 7 . (b) Shows an SEM view at 7500X.

B

:

:
135

Figure

8.

TEM

micrograph

of

as-cast

2219

aluminum

alloy.

Dark

interdendritic

phase

is

0.

Light

interdendritic

material

is

a-Al

.

0'

precipitates

are

faintly

visible

within

the

dendrites.

Precipitates

along

dendrite

grain

boundary

have

not

been

identified.
1

aluminum

alloy.

Diffraction

pattern

was

obtained

from

light

circular

region,

defined

by

the

selected

area

aperature.
137

Figure

10.

Cu2

FeAl

7

interdendritic

phase

identified

by

electron

diffraction

in

as-cast

2219

aluminum

alloy.

Diffraction

pattern

was

obtained

from

light

polygonal

shaped

region.
m

138

a -t-j c c

•r— <u E to

Z3 o> r— S- <o Ql

crv (U

r~~ sC\J <o CO

to

4-> 4-> to c

<om

O •f— 1 s- to fO

«a > c 4-> •r" jn

O) fO JC

•r“S- 4-> a C c o;

CJ S- •o OJ 4- r— 4- c •r- 1 *o a

<u c <D

(O i-

»4- t— O

S- . o —

•p—

O

S-O) O) +J s- c fO

to

<u O) JC +->

+-> to +J c •I—

•r" Q.

•r—

4-> o • r— cu s S-Du

toO) (U

4-> 03 h-

+-> •r-Q. • •r“ >> U o

O) 1—

S- 1

a. to

cu

SrsCD *

PIm
139 E

13 r~ • (O —O

cn1— HCM O

CM

C

+-> o

V) •rTM fO -4-> U <o 1 <D

</3

(T3

O3 C c

•r~ s-

<u o 4J 4-

•r—s- to -o (U c 4-> <D •r- T3 to ,

o <C (V 1 s_ a scu c M-

(T3 CU

SV|- CL O

U)

i- 03 O

•f— +J

S- CJ

<L) fO

4-> C to

•r— CU

cu fO -M -a c 5

•r- o

X3

+-> X) • 1

Z3 3 to

to CU

OJ to

•r* cu

s- 1— oc

rs • o >3 JD o

J3 1—• 3 r—

t/3 03

CSJ

<u

S13cn

•r— U_ I
Figure 13. Typical SEM view of interdendritic eutectic

near the chill face of DC cast 2219 aluminum

alloy; a-Al , irregular rounded particles of

CUAI 2 and blades of Cu 2 FeAl 7.
141

I

Figure

14.

Optical

micrographs

of

DC

cast

ingot

at

different

distances

from

the

chill
142

CO lO

Figure 15. Macrosegregation profile, average copper, iron and manganese

content versus distance from the bottom chill, in a unidirectionally

solidified reduced cross section laboratory ingot of 2219 aluminum

alloy. Cq's denote the average content of each element.

, %

MANGANESE

(
143

Figure 16. Typical SEM view of interdendritic eutectic near the

chill face of laboratory cast 2219 aluminum alloy ingot;

a-Al, irregular rounded particles of CuAl? and blades of

CujFeAb.
10-1

REDUCED

CROSS

SECTION

tABORATORV

INCOT

OF

2219

AL

ALLOV

144

tfi

UJ

e:f- o • >>

<u

O

O I—

-*-> r— r“

Id E Id o E

J- «+- 3

»- o c

•r“ in c E

O)O 3 o -f— r— c +-> Id

<a Id

-*-> o cn

in >r— f—

•r“ M- CM

T3 •>- CM

“O

l/> -f— «4- 3 r— O O O

•r- in -<-> S- O

«3 I— CD > <o C C

4J

O

fO *r— >) 4-> t. (U O O E O) 4J

5- <o +J -I- S- -o O

in T— 3 C Id

1/) 3

&-

OI (U c > sz o

+-> <u +-> S- C3 u 3 C 0)

-*-> *1-

m

id $- i- 3 in

0) -O in a. O E I— s_

<U 1—

+J T- o ^ -o

T3

O (U <U o

S- E 3 3 0-0

in +-> (U

Id -t-> i- 0) o

z: jn 3
. %

COPPER

(

145

Figure 18. Average copper content and electrical conductivity versus distance from

the bottom chill, in a unidirectional ly solidified reduced cross section

laboratory ingot of 2219 aluminum alloy.

CONDUCTIVITY,

%

I

ACS

(-
, %

COPPER

(

146

0) lO

80

70

55

DISTANCE FROM BOTTOM CHILL, cm

Figure 19. Hardness after thermomechanical treatment to the T87* condition

and copper content versus distance from the bottom chill in a unidirectionally solidified reduced cross section laboratory ingot.

HARDNESS,

HRB
, %

COPPER

(

147

Figure 20. Conductivity after thermomechanical treatment to the T87*

condition and copper content versus distance from the

bottom chill in a unidirectional ly solidified reduced cross section laboratory ingot.

CONDUCTIVITY,

%

lACS

(-
, %

COPPER

(

Figure 21. Tensile and yield strength after thermomechanical treaiiment

to T87* condition and copper content versus distance from

the bottom chill in a unidirectional ly solidified reducea

cross section laboratory ingot of 2219 aluminum alloy.

STRENGTH,

ksi
149

*Tr

I

1 cm

Aluminum Samples

Stainless Steel

Rod

Thermocouple

Locations

Figure 22, Schematic of jig for holdir.a four aluminum alloy plates

0.64 cm X 2.5 cm X 17 cm (1/4" x 1" x 6-1/2") for

simultaneous heat treatment. Four thermocouples are buried

in the samples as shown. Samples are held in place with

stainless steel rods.
TEMPERATURE

TEMPERATURE

i

150

Figure 23. Schematic representation of the thermomechanical treatment

sequences given the 2219-T87* aluminum alloys used in chis

study.

n

p

p
Oo ‘3aniva3d!/^3i

o

o

iD

Figure

24.

Temperature

vs.

time

profiles

from

the

four

thermocouples

in

an

aluminum

alloy

plate

0.C4

cm

x

2.64

cm

x

17

cm

(l/4“

X

1"

X

6-1/2")

given

a

simultaneous

heat

treatment

of

the

sequence

A

type.

(Thermocouple

placement

In

illustrated

in

Figure

1)

.
152 i

P

Do ‘3dniVd3dlM31

Hquro

25.

Temperature

vs.

time

profiles

for

alloy

plates

'v.

0.64

anx

2.54

anx

17

an

(l/4“

x

1"

x

6-1/2")

given

a

heat

treatment

of

the

sequence

U

type.

Temperature

represents

the

average

of

thermocouples

placed

as

Illustrated
153

Figure 26. Scheiratic of tensile test specimen. Dimensions are in rrm.
REDUCTION

OF

ELONGATION

ULTIMATE

TENSILE

YIELD

STRENGTH

AREA(%)

{%)

STRENGHT

(ksi)

(ksi)

154

i

PERCENT STRETCH

P

Figure 27. Mechanical properties as a function of stretching for 2219

aluminum alloy. Samples were sol utionized and quenched prior

to stretching, then aged for 15 hours at 172°C (solid lines P

and circles) or for 18 hours at 177°C (dotted lines and triancles.

P
aai9

AL

ALLOV

ia-3-79

155

x<ro:QZLutncn XQIA

Figure

28.

Rockwell

B

hardness

asa

function

of

stretching

for

2219

aluminum

alloy.

Samples

were

solutionized

and

quenched

prior

to

stretching,

then

aged

for

16

hours

at

172“C

(solid

lines

and

crosses)

or

for

18

hours

at

177“C

(dotted

lines

and

circles).
HRB

ys

5<IACS

-

SOLUTION

HEAT

TREATED

aai9-T87*

PLATE

r-n

(Dn

cn

n

n

n

njn

m

o

n

ifi O

<r

I—

o

D

Q

2:O

O

o O

LO

O O

(D

<S) OJO <S)

<XQiQz:iij</)cn XQiia

Figure

29.

Hardness

vs.

conductivity

for

2219

aluminum

alloy

given

a

solution

heat

treatment

and

a

salt-bath

pre-aging

treatinetit.

Pre-aging

treatjjients

varied

between

250®C

and

47b“C

in

temperature

and

between

2

and

3C00

seconds

In

time.
HRB

US

«IACS

-

SOLUTIONIZED

AND

STRETCHED

aai9-T87*

PLATE

157

x<xo:ozLLicncr)

Figure

30.

Hardness

vs.

conductivity

for

2219

aluminum

alloy

given

a

5%

stretch

after

a

solution

heat

treatment

and

a

saltbath

pre-aging

treatment.
HRB

CHANGE

US

?<IACS

CHANGE

ON

STRETCHING

-

2319

in

OJ

X X o

ox 00 (

X

X 0

m

X ox

X oo xo

X XXX O

) X 9< X O

X

cm

o xx«>

ox t>CX O 0

< xsr X a 0

0»

xi<xma>o

0 XKflBK

ytaoaot. X

XCX X XO X

XXX

X XX XXX

>0K X XK

K>ax X

XX X

X 0

\—I

\

1 1 1 1

\ \ \

! ^ 1 1

\ \ o o o o o n ru ^

o

0

<s

1

in

cu

I

o

LO

0

1

in

0

1


 o

in

fU

LU

o

z:

<xX

o

cno

<r

if

XQ^ca ox<rxouj

Figure

31.

The

change

In

sample

hardness

vs.

tlie

change

In

sample

conductivity

which

occurs

In

solutlonized

and

pre-aged

2219

aluminum

alloy

upon

stretching

to

b%

permanent
HARDNESS

US

CONDUCTIUITY,

aai9-T87*

159

x<iQ:Qz:ijtJcncn XaCQ

CONDUCTIUITY,

HIACS

Figure

32.

Hardness

vs.

conductivity

for

2219-T87*.

The

solid

line

represents

d

lesst

sQUdres

Qusdrdtlc

fit

to

all^the

ddt

and

the

dotted

lines

a

scatter

band

(approx.

95*^

confidence

level

).
HRB

AFTER

US

HRB

BEFORE

(lACHINING

PROCESSED

3219-T87*

xoroa <iu.t-ijjQ:

Figure

33.

The

hardness

obtained

after

njachininn

approximately

0.6

nin

from

the

surface

of

aged

2219-T87’*'

alloys

plotted

asa

function

of

the

hardness

obtained

before

machining.

The

solid

line

is

a

linear

least

squares

fit

to

the

data

^x)ints

and

tJie

dotted

lines

are

the

scatter

band

9b%

confidence
XIACS

AFTER

US

XIACS

BEFORE

MACHINGING

PROCESSED

3319-187*

161

(Ji n

00n

r-mm

If) n

'T* nn

cn

OJn

LiJ q:o

ii_

LJ

CCk

(f) o

<x

t-H o

LT> (U C3\ >> <« I— +-» <? I— (B —

0» T3 *3

•4-> <u • "a

iB 4<> 3) 01 3 £ •(-> 3 ^ B

-rO X

C o q i- i. ^ -M o; O. u +-> a. >» <3 -M

(B

O cs <B r— M- U

cj^ <a i/> C (B 1. (/) o 11 01 C -ic (4- 1. ^ ^ 01 .B ^ CO XI 3 0 I— * 01 B • ^ ^ C CT 4-> B

P*

i- rj > 1/1 </i 01 CM •»“ B <11 +J 4J a c

<4- -o

a r— -rB 03 3 f—

3V3 i- "3 B 3 B "O

01 0 3 3 3 U 3 -•_> t- O -r- . B 01 r— C M 01 JO "3 I—

j3O +->B 3 OB 3 >

<+- ‘4- i/l JZ 3

SO r—

-t-> 3

•»- VI 3 01 -3 01 > O 3 3 01 •r- 01 T— -f— B — 4-> 31 3 0^0 V> "3 3 O'a-M-r- 3 S 3 3 3 O ‘+- ' 3

05-

O

C

O

OJ <4-

B 1/1

—

O

PO

01s.

ie*-»<rocn <ru.i-ujQi
aai9-T87)*^

VIELD

STRENGTH C

CURUES

FOR

SEQUENCE A

Figure

35.

Yield

strength C

curve

representation

for

sequence A

alloys.

The

curves

give

the

critical

times

for

obtaining

the

indicated

yield

strength

(0.2%

offset)

for

an

isothermal

sc(|uence A

type

heat

treatment.
aai9-T87*

YIELD

STRENGTH

C

CURVES

FOR

SEQUENCE

B

163

t— UJ^Q.LdQ:<rt— ZDQiUJ QUJO o

Figure

36.

Yield

strength

C

curve

representation

for

sequence

B

alloys.

The

curves

give

tlie

critical

times

for

obtaining

the

Indicated

yield

strength

(0.2%

offset)

for

an

isothermal

sequence

B

type

heat

treatment.
a219-T87*

TENSILE

STRENGTH

C

CURUES

FOR

SEQUENCE

A

H-LiJs:Q-UJCi:<rB-Z3Q:uj qujo o

I'igure

37.

Tensile

strength

C

curve

representation

for

sequence

A

alloys.

The

curves

give

the

critical

times

for

obtaining

the

indicated

ultimate

tensile

strength

for

an

isothermal

sequence

A

type

heat

treatment.
165

• -0

u> <U o m

F» (J

<ua.

>» (Q'aC CQ CD*^

<U 0) (U U

0-1= s= C 4-» <U

<U 3

3 o> cr arc (U

OJ 1— «>

VI C

r—

i. «o 2 O-M s H- J3 c

O <u c J= o c •«- o o *-><*-

<9 •M U1 c o c

0) E lO

l/» 0> -M s. U o

a lo

<4-

s- u c/1 -C

0) 4-> -M >-.- CT

i. s. c

3 O 0) u c

a 4->

v/1

0) +j <u CT> C 'f— 1/1 c

a cn 3 qj i- <y E +J 1/1 -M 4-> ui O

> O 05 O S- -)-> s. r— 3 (O -*-> O cz

1/1 T- 4-> C OJ •<-> (T3 ojc: I— a

I— >— 3 -=

« COro0

u

3

01 u.
aai9-T37*

HARDNCESS

C

CURUES

FOR

SEQUENCE

A

166

{- uz: Q. uj Qi <r I- 3Qi uj QLlIO o

Figure

39.

Hardness

C

curve

representation

for

sequence

A

alloys.

The

curves

give

the

critical

times

for

obtaining

tlie

indicated

hardness

f^or

an

isothermal

sequence

A

type

heat

treatJiient.
aai9-T87*

HARDNESS

C

CURUES

FOR

SEQUENCE

B

167

ujsiq-ujq: <r j— zdq:uj qujo o

Figure

40.

Hardness

C

curve

representation

for

sequence

B

alloys.

Th

curves

give

the

critical

times

for

obtaining

the

indicated

hardness

for

an

isothermal

sequence

B

type

heat

treatment.
aai9-T87*

CONDUCTIVITY

C

CURVES

FOR

SEQUENCE

A

f-uiz:Q.LLiQ:<ii-zDQ:uj qujo o
aai9-T87*

CONDUCTIUITY C

CURVES

FOR

SEQUENCE B

169

Figure

42,

Conductivity C

curve

representation

for

sequence D

alloys.

The

curves

give

the

critical

times

for

obtaining

the

indicated

conductivity

for

an

isothermal

sequence B

type

heat

treatment.
CURUE

COMPARISON \ o o

UJ

U)

UJ

z:

I—

f—

<ro

QLo

(Uim

<u

uo

OJ <4-

<0 (/) (U +-> !/1 = O) ^ <u c ^ vj *a

<u

u • u i- *^0) a

&.C2 =

-O -M

Oi i/>

— «3 c a»— a

•»- > 0) i.

to i- 2 4-> 4-» 3 ^ u u -»-> O O «3

O)d (/> ^ —

<u t— <a > <y i. O i2- =U U'V- • = ^= O 1“ < ^ rs

O) 4-> CJ V> +-> "'J a a 3 = 3 = 3

-3 f3 S_

i. s_ o “

fO ‘+“ 3 ^ ^ tn

</> '+-3 3t— o -!= s C3 CO ‘4-

(/IO r—

—fO -*-> ^ 3 O 3 T- 1/1 3. 3 4J •*- 5 (13 S- 3 O > 3 .13 m33

31

F-UJE:Q_LiJQi<E!“IDQ:UJ QUJO

O >
est.

std.

dev.,

%

est.

std.

dev.,

%

eet.

std.

dev.,

%

171

>

-o

•o

iO

CO0)

Figure 44. Estimated standard deviation for changes of only one C

curve parameter at a time in the sequence A values for

yield strength.
VIELD

STRENGTH

(0.2«

OFFSET)

US

HRB

-

aai9-T87*

a>


 00

«s>

o

CD

S)

LD

<S>

m

q:

cn

CO

Ld

2:

o

q:

>«~«UJJCi COt-Q^LiJZIOt-X b^CO*-»

Figure

45.

Comparison

of

yield

strength

vs.

hardness

data

with

the

correlations

predicted

by

the C

curves.

The

dashed

lines

are

the

scatter

band

('v-95%

confidence

level)

obtained

from

a

least

squares

qiiadi'atic

fit

to

tlje

data.
YIELD

STRENGTH

Od.aU

OFFSET)

US

XIACS -

aai9-T87*

•o

(U

19 -a

ut

(O -a

<Q (U -M o) r~ ^

(O J= CU 4-> T3 1— >« 2 a > <2i U -r- •mug; u 3 *3 a 3 a -r- 1-

-a H— -M 3 U 3 ra O O S- U 0) U T3 JZ ta • -M ^ 3

La) sJ > >»CT> 3) C> W) j= ^ a

-M -3 i- 3> a; "3 113 3 -M 3 3 3 U (tJ O’

i_ »“ -3 (/> M -3

(/) 3 U -M U 3 M

*3 (t3 P— -M3 3 (rt <a «— •^3 3

>1

O

H- -M 3 S O (Z JZ o 3 3 3 SL/1 3O

i- 3

(O 3

i- “3

(3 3 O

Wl *r- 3 3 iQ M -M

t- *f- a3 S ^ O

LO3U3

3)

® to ^

in

<S LT) <9 LO

LD

n

u^t-crujz:of-x
ULTIMATE

TENSILE

STRENGTH

US

HRB

-

aai9-T87)|f

o

CO


 ro

LD

<£» X

cnCD

UJ

Q

CL

<r

t— ujxcn»-H JLU

Figure

47.

Comparison

of

tensile

strength

vs.

hardness

data

with

the

correlations

predicted

by

the C

curves.

The

dashed

lines

are

the

scatter

band

('c

95

^^

confidence

level)

obtained

from

a

least

squares

quadratic

fit

to

the

data.
ULTIMATE

TENSILE

STRENGTH

US

HIACS

-

aai9-T87*

175

Ld J— ldZCn*-iwJUJ

Figure

48

.

Comparison

of

tensile

strength

vs.

conductivity

data

with

the

correlations

predicted

by

the C

curves.

The

dashed

lines

are

the

scatter

band

95%

confidence

level)

obtained

from

a

least

squares

quadratic

fit

to

the

data.
ULTIMATE

TENSILE

US

YIELD

STRENGTH -

2319-T87»

176

nn o

(0

LO

10o

L0

LDO

'T

LDn


 o

00 <s o ®

LO LD -T

(/I <u

s.

(U (O JZ 3

4-* O'

CO

lU

im. 4-> IQ CO

OJ (O ^ </» <u 1 4-* lU r— i ^ c 1 4J »—

•»“ £ 3 -3 O i Ol 1 4J (/I <-

CT (O -o i C T3 O)

O) c

i- O)

<T3 (/I >— 4>> j3 *—

o O

LD 1—

0) (/) •*'*“*» T- <u >» > 0) i- > X • 3

v>

u

<u t- > o __ CJ 0) X 4-> O)

CJ UJ 3

q: 3 w

(U • i— i_ ^ -T3 LD 3 -M

CO

O rs » U -O

Q 0)

a

I— 4J >a O) LU

T- o IT3 3:

(/) -r- Ol

w

1—

C -3

0) O)

4-> &. o

a. } 4- )-> 1 O CO o — t c 3 *4- j c o <T3 O 1- — U

co -r— i- !-> * 1_ .— OJ (T3 j <a oj S_ i s. s_ -<-> "3 t £ s- 03 03 o o CJ 3 I o u CO C" i o

O)3

a>

t-UJ2:CDi-i*-JLLl LDt-QiLJZ:Ot-X
HARDNESS

VS

CONDUCTIVITY -

2ai9-T87*

ut

0}

t- -a

<u ^ o f s

-*-*

T3

01 (TJ ^ x: 4-> J3

•»- «3

O S -a i

(O OJ f— rtJ •4J jc oj *a

<0 H— >

*a oi oj >> • M u» o

•r- OJU > > S= t- i_ <u 53

+-> 3 *3 4J U U -t- •»“ 3 H- <+- -3 O C C O <J O OJ U -1— U ^ -fj •M ^ fO • LO U

(/) >>C^ *0 > ja to

1/1 "O

— o*

U) <u

OJ -M -3 VI 3 0 3 3

-3 fO s_

i- -3 -Q ro <0 3 3

S- S- CT 3. O (yl

O w? 4-> +-> 3 (Q (/> 3 O O rt3 O •»“ 3

(/>+-> r—

•r- <o 3

i- ^ j3 3

(O 3 4-> Q. E = i_ 3 O O O S- i- O fO H- oIT}3U3

Cl

x<ro:ci2:LLjcn</> xrroa
RESIDUALS

FOR

YIELD

STRENGTH

US,

HARDNESS

-

aai9-T87*

178

0 ^

X

^ X® * *)j<X

X X

® 0 oX

o

X

X X

Y *

„Xx *

* X X

X X

^

0 5<o o

X ^ X

n X

1

1

1

1

X

X

o

X

0

* , o

xc

‘ O

*

*x

X

X

O O ) „ X

X

O 0

X

X

X

o

0

X

X

0

®

Oo

0

X

0

0

> X

X

X

00

o

iD

o

in

o

(/) (U c

3 S. f— o

(Q ^> 0>

A

QL

CO

tfi Ld

z:o

q:

<cX

-a

O) • (T3 o -t-> •r- (TJ *a "o

(U^ cn Q. I/) <u

1/1 c

<U "O u s- « (O 3 XZ

a*

(/I • (/) 4-> >

1/1

(T3 ^<U «-> r— 01

1/1 <v 3 5-

t/1 3

(U O) 3 >)

i/l fO <*- O) o • =

</i <+- aj r— S-

(T3 OJ 3 3 ^ 31 -3

t/1 s- 3 0 3

CC

LO3

31

OJ o fU

I 1

aUJ CO O3<X JCO xo:tt
NORMAL

PROBABILITY

PLOT

-

Y.S.

OS

HRB

-

a219-T87*

179

Q: LU (/» *-i Q3 <r -J CO xo:tt

Flqure

52.

Normal

probability

plot

of

residuals

from

the

least

squares

fit

of

yield

strength

vs.

hardness

data.

Shown

in

Figure

45.
COMPARISON

OP

aai9-T87*

AND

705O-T76 C

CUROES

nR

O

UJ

(/)

<zo

q:o

trt r>. c ^ C3 (Q (Q h— S- U I cr>

LlJ

— T- fO

CM +-> i- CM a u

v»-—^ a

oj

a > I— <u

C

V

TV > o o

cn ^ (S ^ 3 P u tyi -a

<_j -a <u

(T3 CJ = C 3 C U1

n3 (/>

(T3 ^ (a -p f3 p o

3J

O r— 3 3: CP

(Uu

S- 3

-p <a •

!/> > O LU 1^

-a ^— >— >1 I O J3 O 1- LT) >»-a o a

<U 3

Jdt- P 4J = o P <4- O -P

i) «i3‘

O cn

in CJ I—

-rC P O « fB ro

CL.3 -a-

(U 3> P CJ O iiO P

in < T3 a a u^ >; a PP

a-'rZ3in 3o

(T3 •’— P P C 3 P "3a

in P 3= ^ Q *T“ « P3 5 IP • CO

in

<up3

Oi o o 
 o IS) n cu

i-uj£:cLLLjQ:<r£-3Q:uj qluo o
ALUniNUn

ALLOY

2319-187

4-4-80

181

CO

n

CD

n

CD

CD

CD

O

CD

CDO

<X

t-4

S

Dto

o

z:o

o

>«-»uj-jQ cnt-o:Lijz:ot-x

Figure

54.

Comparison

of

yield

strength

vs.

hardness

for

2219-T87*

as

deteiTiiined

by

four

laboratories.

The

lines

represent

quadratic

least

squares

fits

to

the

data

from

the

different

laboratories,

as

indicated.
Atomic Percent Cu

Weight Percent Cu

Figure 55. Al-rich portion of the Al-Cu binary equilibrium phase

diagram, with G.P. zone, 0

" and 0' metastable boundaries.

From Lorimer (19) .
183

Figure 56. Optical micrographs showing grain structure of as-received plates

of 2219 aluminum alloy (lOOX), (a) 0.625 cm thick plate in the

T87* condition, (b) 3.81 cm thick, plate in the T851 condition.
Figure

57.

Optical

micrographs

showing

grain

structures

of

resolutionized

and

quenched

plates

of

2219

aluminum

alloy

(lOOX),

(a)

Initial

material

0.625

cm

thick

T87*

plate

(b)

Initial

material

3.81

cm

thick

T851

plate,

(c)

Initial

material

0.625

cm

thick

as-fabricated

(F)

plate.
185

+J

c:(Uto

0) c •o i- a> OJ Q.

E N

•r— to u E c

O) •rTM o

Q. c

(/) •r— 4J

•«—

E

a o +J o

a; <a t—

JC sz to a +-> •r- c: XJ

CU "O • Z3 OJ (U iA cr to O) 3 4-> •r~ "O S-. c: O) 4- fO

fO S- o -a

OJ c

X) s 4-> 3

<u CO O

4-> to O Jd a s: jQ

O) o 3

l- sz lO

+-> +-> • cu to X3

4-> E c c

ra o fO

<D c •r“ o +-> to

•r~ (O -V c +-> o &- o fO o o

•r— s- r~— 2 +-> <o to 4-> 3 CL •r- O) r— CU -O c= o f

(/) CL 4- x: o +-> 4- OJ •r- O r“ c 2

CL o

E •1— X

Q- fO +J OJ (O CO u +J

i~ 3 (T3 oi X •r~ o • o u

S- t- o

u to +-> to

•r“ CM c to E

CT^ •r" 03 s: <u OJ UJ CO JC s- 1— =«: 4-> 03

00

LD0) s_

Z3cn
186

Figure

59.

Dislocation

network

in

as-quenched

specimen

(#879-26).
Figure 60. Low magnification STEM micrograph showing various phases that were

subject to compositional and diffraction analysis. Q and Q' were

found to be Cu^FeAU, L and E were probably this phase also. R

is as yet unidientified. Specimen #197 solution heat treated at

535°C for 75 minutes and quenched in ice water.
188

n

Figure 61. High magnification bright field image of Q shown in Figure59 with

corresponding electron diffraction pattern and x-ray spectrum that

identify it as Cu^FeAly.
189

Figure 62. Precipitate R shown in dark field with corresponding x-ray

spectrum. In addition to A1 the precipitate contains a high

concentration of Mn, Cu and some V. The precipitate may be the

phase CUpMn^Alp^. The x-ray spectrum from the a-aluminum

matrix is afso^shov/n. Only A1 and Cu are present. The concentrations

of other elements are too low to be detected.
190

Figure 63. Micrographs showing dislocations and a few scattered inclusions

in specimen which had been solutionized, quenched and stretched

2 1/4/a (specimen #1). There is no evidence of a homogeneously

distributed major precipitate phase.
191

Figure 64a. Microstructure after resolutionizing and reprocessing to T851

conditions. Fine spots in the accompanying diffraction pattern

serve to identify the precipitate phase as 0'. Specimen #1A.
I

192

Figure 64b. TEM micrograph of specimen taken from T851 3.81 cm thick plate

in as-received condition. The structures shown in Figure 64a

and b are essentially identical. Specimen #879-55.
193

Figure

65.

Microstructure

after

reprocessing

according

to

T87*

specifications

(specimen

#142).

A

high

concentration

of

0

precipitates

is

present.
194

Figure 66. (a) Bright field micrograph showing relatively large- 0'

precipitates and smaller G" precipitates. A cluster of 0"

is present near the center of the photograph, (b) Electron

diffraction pattern with intense a-aluminum matrix reflections

and 0' reflections. 0" reflections cannot be distinguished.

This specimen (#94) was given an interrupted quench at 400°C for

15s but otherwise was treated according to Reynold's T87* process.
195

( 020) A Q

( 220)^

(003)^..

(002 )^.

Fig 68 (b)

. I / V

t

(002)^.. I

(001)^.. I

Fig. 68 (a)

(000)

(200)q

Figure 67. Schematic of diffraction pattern showing diffraction spots

from which dark field images in Figure 68(a) and (b) were obtained.
Figure 68. (a) & (b). Dark field micrographs demonstrating the presence

of o". (a) Only o' is imaged; operating reflection is (101 )q, . (b) Both o' and o" are imaged; operating reflections are (002) , and (003)^,,.
197

Figure

69.

Typical

microstructure

after

solution

heat

treatment,

ice

water

quench

and

aging

at

177°C

for

18h,

i.e.,

T851

without

2

1/4%^

stretch.

Bands

of

large

o'

precipitates

are

seen

together

with

uniformly

distributed

fine

0"

precipitates

(specimen

#879-35).
I

198

O) X) SI <D

4-> "O

rs sz c +J <u o a • CQ O'—

C onn

00 . cro to

Ol 00

o» c 4t= S- 03

zz fC

C71 CL OJ

•r— E

U. *-> •r"

•r— o c -Q OJ

•r* to Q. SZ to C5 •/'—

O o <jn OJ 00 r— +->

'-r-' (O

to +-> OJ OJ •f— +J > Q.

rO ro • r—

+-> sz

U

•r— O) Q. 00 S-

•I— (U Q. O +-> 0) fO —

i. +J o

Q. •r—Q. OJ 4- *r“ cn O o S- OJ fO

(U t- r—

CD Q.

«3 OJ JE z jn O +-> C , *o o r— c

fO 13 +J E o

(0 to s- u fO

•r- *a

4- c to

•r- fO 4-> C to O) — •rTM fO o X E

QJ OJ sz CD OJ O) S- c

•r— 03 o

nr f—

N o

cu

i-rjcn
199

Figure 71. SEM micrographs of specimens after various sequence A quench

treatments. The specimens were etched to reveal the presence

of precipitates formed during the quench treatment, (a) Specimen

#197, quenched without an interrupt, (b) Specimen #93, pre-aged

at 400°C for 15s, (c) Specimen #81, pre-aged at 400®C for

30s, (d) Specimen #85, pre-aged at 400®C for 60s.
200

n

I

n

Figure 72. SEM micrographs of sequence A specimen #69, pre-aged at 400®C

for 30s, a) Low magnification, b) High magnification.
201

Figure

73.

TEM

micrograph

of

specimen

#85,

pre-aged

(sequence

A)

at

400°C

for

60s

Both

0'

and

0

precipitates

are

present.
Figure

74.

Same

specimen

shown

in

Figure

73.

Misfit

dislocations

can

be

seen

at

the

interface

of

many

precipitates.

Numerous

strain

induced

dislocations

are

present.
203

o0) JZu

4->

+J

’ o 5- ^ G

<_> <u o cr> o ^ o ® ^ ' +J 0) -R c M-

•r- O

o>

ITJ

I

(U +J

to O

<u 2: 4->

<T3 4-> • •r- 01 Q. C

•r— 'rTM O CT

. O) <0

S-Q. C • O toCU O -o 1—

(U a

CU a -r- C =5 4J

•r- X) S- U_ O rtJ i~ CL Cl

. CU -a O) CD o $- s- CU CO

S- s -—

O)Cl

>5 C

C 4-> SCT) c

<U 03 Q. CU "O

s_ 2; 3 +-> C

Q. S- -»-> 3

S- fO 0 C • OJ a. i. SZ +J SO) t£) C C 3

0 r- •r- 0 to c •r— a> s- <U +-> to 3 0 ^ a c

0-4- 4-> 03 0

(U S- •!- to 0 cn4_ 03

0 C 4- <U C CVJ •r- •!- S- oj r'. s- -0

> 1— 3 CU

• r- -0 c CU CO +-> •I- S- 03 -o 4- to O) to 00 "O O +J CU

=«= O) 3 0 +-> cnxi Q. fO C to 0 to 4-J <U i- •>- E -O Q.I— CL

•I- c f— • r

0 fO CD n3 U

CU S- E CU Q-^ OJ to SC/3 tn CL

tn

<u

i13CO
Figure 76. Dark field image showing two 0 precipitates in bright contrast

at a grain boundary and in contact with an inclusion. Specimen #105.
205

Figure

77.

Specimen

#6,

quench

pre-aged

(sequence

A)

at

350®C

for

15s.

Many

0'

precipitates

are

identified

ata

and b

on

two

different

{100}

habit

plane

variants.

Note

black

appearing

particles

associated

with

0

'

precipitates.
I

206

Figure 78. SEM micrographs of specimens after various sequence B pre-aging

treatments. The specimens were etched to reveal the presence

of precipitates formed during the quench treatment, a) Specimen

#249, reheat to 450°C for 15s. b) Specimen #253, reheat to 450°C

for 30s. c) Specimen #232, reheat to 400°C for 30s.
207

Figure 79. TEM micrograph showing 0' precipitates formed during reheat

400°C for 30s. Specimen #232. (Sequence B pre-aging.)
208

Figure 80. TEM micrograph show'^^g precipitates from which x-ray spectra were

obtained in Figure 81. Specimen #249, reheated to 450° for 15s.

(Sequence B pre-aging.)
209

pp- S 100SEC 0 I H T u=2048 H=10KEU 1 10 rt0=101E" 10

AL

• CU

n ^n^E" XES \a \ e'F"

Figure 81. X-ray spectra of precipitates shown in Figure 80. a) Precipitate

A. b) Precipitate B. Note, low energy Mn peaks which are labeled

can not be detected above background, c) Precipitates at Z.
210

Al-1.95wt .%Cu

Figure 82. Nucleation diagrams for Al-Cu alloy from Reference (26). (a) Al-5wt%

Cu alloy, (b) Al-1.95wt?j Cu alloy.
217

x/L

Figure 33. Dimensionless temperature profiles as a function of time in a plate subjected "o symmetric cooling from both sides with a Biot num.ber of 5.0.
212

Figure 84. Dimensionless temperature profiles as a function of time in a plate subjected to symmetric cooling from both sides with a Biot number of 0.5.

I

I

I

i

P

P

P

P

i

I

I

I

i

i

I

f

I

I

I
213

t, s

10 20 30 40 50 60 70 80

Fo

Figure 35. Calculated time- temperature profiles at four locations in a 15.24 cm thick plate of 2219 aluminum alloy cooled symmetrically

from both surfaces from an initial temperature of 555 ®C.
MINIMUM

YIELD

STRENGTH,

Ksl

/

214

T T

35.0 0 5

I 10 15

PLATE THICKNESS, L (cm)

Figure 86. Predicted minimum yield strength versus plate thickness for

plates cooled from she top surface. The minimum value

corresponds to the bottom surface of the plate or the canter

of plates with twice the thickness, but cooled from both

surfaces.
TEMPERATURE,

215

o

o

igure

TIME, seconds

0 50 100 150 200

37. Calculated time-temperature profiles at four locations in a 12.7 cm thick plate of 2219 aluminum alloy subjected to an abruDt discontinuation of heat extraction from its bottom

surface.
HARDNESS,

HRB

216

Figure 38. Predicted hardness versus distance from the top surface of

12.7 cm thick plates subjected to a variety of heat flow

conditions at their bottom surfaces. Curve denoted by

T = 0.02 is for the time-temperature conditions shown in

Figure 87-
YIELD

STRENGTH,

Ksl

217

x/L

Figure 39. Predicted yield strength versus distance from the top surface

of 12.7 cm thick plates suojected to a variety of heat flow

conditions at the bottom surface. Curves are calculated using

constants in Table VIII for sequence A.
YIELD

STRENGTH,

Ksi

218

Figure 90. Predicted yield strength versus distance from the top surface

of 12.7 cm thick plates subjected to a variety of heat flow

conditions at the bottom surface. Curves are calculated

ijsina constants in Table VIII for sequence B.
219

TIME, seconds

0 20 40 60

Fo

figure 91. Calculated time-teiriDerature profiles at a given location

in a 7.62 cji thick plate or 2219 aluminum alloy subjected

to a variety of heat flow conditions at the bottom surface.
YIELD

STRENGTH,

Ksi

x/L

Figure 92. Predicted yield strength versus distance from the top surface

of 7.62 cm thick plates subjected to a variety of heat flow

conditions at the bottom surface. Curves are calculated using

constants in Table VIII for sequence A.
YIELD

STRENGTH,

Ksl

221

Figure 93. Predicted yield strength versus distance from the top

of 7.62 cm thick plates suDjectea to a variety of heat

flow conditions at the bottom surface. Curves are calculated using constants in Table '/III for sequence B.
HARDNESS,

HRB

0 0.25 0,5 0.75 1.0

x/L

Figure 94. Predicted hardness versus distance from the too surface

of 15,24 cm thick plates of 2219 aluminum alloy subjected

to a variety of heat flow conditions at their bottom

surfaces.
YIELD

STRENGTH,

Ksi

223

Figure 95. Predicted yield strength versus distance from the too surface

of 15.24 cm thick places subjected to a variety of heat

flow conditions at the bottom surface. Curves are calculated

using constants in Table VIII for sequence A.
YIELD

STRENGTH,

Ksi

Figure 96. Predicted yield strength versus distance from the top

of 15.24 cm thick plates subjected to a variety of heat

flow conditions at the bottom surface. Curves are calculated using constants in Table VIII for sequence 3.
MINIMUM

HARDNESS

HRD

225

Figure 97. Predicted minimum hardness in different thickness plates under the

"worst possible" heat flow conditions.
MAXIMUM

CONDUCTIVITY

%

lACS

226

n

figure 98. Predicted maximum conductivity m uiiier^iri

the worst possible" heat flow conditions.

in difrerent thickness fj I a uiiuei
MINIMUM

PREDICTED

YIELD

STRENGTH

ksi

227

L, INCHES

Figure 99. Predicted minimum yield strength in different thickness plates

under the "worst possible" heat flow conditions using sequence

A or B data.

M

Pa
MINIMUM

TENSILE

STRENGTH

ksi

228

Figure 100 , Predicted minimum ultimate tensile strength in different thickness

under the worst possible" heac tiow conditions.
229

JJ

Figure 101. Geometry of aluminum samples used in the round robin. Each

sample has an identifying number stamped on one end as shown.

The sample surface was divided into three equal areas. Each

laboratory made three hardness measurements in each of the areas

H and three conductivity measurements in the area marked C.
eai9-T87* -

ROUNDROBIN

BY5

LABS -

1980

230

««nir9^u> • • • • • ooooo sxxzx • • • • • ^ /

*•

® ^ X - •s.

—11

CROSSES .

LAI

CIRCLES -

LAI

SQUARES -

LAI

TRIANGLESLAI

STARS -

LA!1 1

t) 4 • 0 • X * 4 • A « X «• a 4 • O s 4 « 4 XO S X *m 0 ^ 4 • «

«- 4 . 0 1

•e «

f, «

Fit* F

00

cnn

CO

cn cno

<r

un

cn % >

f—o

13O

cn oo

cn

cn

fU

cn 9

O) o

00 o

c^ o

CO 9

U)

«/)

V 0) <Ur— c L. a.

01 E

T3C 01 </) 3 ^ <4- o Q. O 01 u 01 c

L. 01

O

>> 3)

4-> >0 3 3 i- O

01 o > >>

-t-t Q. IT3 ^O

J3 01 •*») o U ^ <3 (Q W U

-o UJ

O

01 3J ^3 'Q

~r— . (O r—

<a >>

-4-i o </> 01 >-•4-13 O <—3 0

ra 01 >» E E 01 ^ 3 i- > 3 3 01 un "3

4->

— 3 u 3 01 E 3 r— =

(Q yi

(/J 3

It y>

U r- 01 -3 =

1/1 1 L. 01 > 31 3 X .— ^ 01

1/1 CM

A

'/I CM

X 3

01 1/1 4- /I 3

-3 o 3“

fl Ji o

01 .—

a

SO 3. 3> E «3 > 3 —

r— 01

01 > 3 3 3

•»— •o ^ 01 o o — c

iw

u IIIIIIII

CMO

01S-3
HARDNESS

VS.

CONDUCTIVITY -

ALL

LAB

AVERAGE

231 • i! > ; co O u &. c M to o "O <u to C C 0} (O to 3 to ^ 0) a o r— C • U <0 <U> to 1— r«i» >> <u « tU

4->

C ^ C *3 >

s- -o (U HI tu

•r- i. (/I to JZ .S lO O) <V to M -1- i. <a tu s- Q.*0 o

<U (U o (U 3

J= ^ i. O) tU

4-» (O -a

tu -M •F*

u c o 3 t4- o (U ^ •>- *o 3 >4- .C (T3 f— c O 2 P— tT3 o

*o

+-> >, 0) •F- 3 o > f— O LT> > <— t- O -t- tor •r- r— <4- lO 4-> •M lO to >> u = 0) 3 3 = 0 .3 O* tu TT 3 S- lU 4-> e C <+- (T3 O o = U S t/> • -F— 3 -M tu 4-1 X • f— C 1— ro o

to

a Q. i- > s £ "O ^ 03 fO 1T3 a.

to

u

to CO 3

to 3 iT3

a 1— to -3 C 1 (O O IT3 -3

*0 CT> tu IT3 3 1- f— s= (U O

fO CM 4-> -3

3: CM >, i. 4^ O 4-» OQ <4- -r- H- •!- 0) o > <4- 4-> o 4-> r— to 4-1 O) to tC

0> tuu CD 0)

U 2 1— 3 ITS i- to ^ Q.T3 t. 3 0 = 0 OJ 3 a O fO o > cr.3

q: to o 4-> o

tu3 O o C7> 00 o o o

r- Lfl in
YIELD

US

CONDUCTIUITY -

$LL

LABS -

ROUNDROBIN

232 I C (U3>-0

-Q >» <0 Z 3 O 4-> (T3 u > <u z

•f— > U O) -o (T3 3 C t- 3 U 03 c^ O 3 a

i- T3 <U 3 5 C ^ fO u

<v o 3

x:

u OJ cr>«

•M > LD

0) fO fC CT» (U

O

— o >»

«4- JZ (/> 4-» r—

•M

a CJ >»

•M

U s_ 1— 03

*r“ JZ o 4- > 4-> •M •F— T“ (O’ co X

(Si •M z u a; o

(J 0) o i_ i.

O 3 -Z 3 o

<r ^ s <T3 3 z F—

3" 03 o CO u o 3

r— > 4-> *3 • CO 3

1/J fO 4— (T3 >- > _ 3 1

. 2

OJ '

S_ 1—»

+-> Z Zj fO 3

OJ -f- LO E 4- CO 4>< 4- 3 C

<4>. >

3 u o O (O _ZI a 'A u ^ ->t u

(O

CO

O) 3 a CM r». a 1. z; • 03 O i— O o 1 o s. 3 o O s- ^Z r” u_ CJ •-a +-> CM w

cncM CO (/) z -M CJ 0) 4- z

S.

O GJ 'O •F“ p—

VI lA

a

0) "3

J T3 — 3 on a

Z.. CO

OJ E o a 1 •»- fO a 03 >- W1 s w J III« o

a>3
aai9-T87»

-

ALL

LABS

-

ROUNDROBIN

1986

233

9 Lo 9 in o u)

<n in in n

00

c*i

cn

(D

cn

in

cn

cn

cncn

cu

cn

cnf-QcujzcrtFigure

105.

Curves

obtained

by

least

squares

fitting

the

yield

strength

(0.2%

offset)

vs.

the

Rockwell

B

hardness

of

the

2219-T87*

round

robin

samples

as

measured

by

each

of

the

five

participating

laboratories.
VIELD

ys

HARDNESS -

ALL

LABS -

ROUNDROBIN

Li)

00

00

Li) r-


 rLD

CDo

CD

LD

LD

C 03 *3 O C o 4-» 03 1. </1 c X3

to 3

-o 3 L. c C X 4- 3 3 3 4-> o 3 </l u «3 5» 3 9

(T3 3 3

(U x: 03 to X z

*» •w- to O- 0) to 3

•f" -«-> o 3 L. 4-> »4- O to 0) •M •<-> 03 i-

(/) 3 03 to C L. p—

OJ 3 O to c ,sz 03 3 "3 3i z • L. r“ to •»— <9 4-> >—

,£Z

O 3 z 3 > 3 "3 >

ca • •»— to 3 3

to fO 4- 3 X ri^ 0^ > to X 3 Z. 03 3 3 "O 3

4-> z W Z z % 3 3 3

Ci) to ST 4- 3 X •3

(i)

tt- z w Z 4-> 4-

Ld

O (« r— "t? z U o u

•*c !T3 3

CM r»* 3

O' • CO <r o 1—

w

w -D 1 O C/1 o s_ ^ p— u- a ^

-i-> Csl 3

OCVJ </1

O) z

s- o a

_ 4-> s "3

wi to

a cj -i-J

X

C" 1) CJ -J3 3 =

OJ 1- 3J ^ 3 »— 3 ^ Z. </l a) E «3

ra

a

>- (/I E

1) ^ 3. > 3 "3

toO

U)

(U3 ® Li)

CD Li)

O Li)

Li) 'V

O Li)

®

n cn

ci)f-o:uiz:cJt-x !kici)»-j
aai9-T87*

-

ALL

LABS

-

ROUNDROBIN

1980

23fj

LO

\ .

00

00

U)

r^

<s

U)

CO

o

CO

U)

8^

K A''*

* \vi s X ^

•X

Oo

f

X

\ « ^ •

—run^io

* \'\

t\N:4'fv 00000 zzxzz

AACD AtiBC

1 1 1 1 1

0

V\\.

1

1

.

SOLID

LINE

.

DOTTED

LIHE

,

DASHED

LINE

S,

DASH-DOT

[)ASH-D0T-D0T

1

1

X‘.\

\ ''

A't'i

CROSSES CIRCLES,

SQUARES. TRIANGLI

STARS.

1 1

%.\

‘''

v X

Li)

<s

I i I I I I I I I I I I I i I I 1 I I I ' LD

O li) CO Li) O Li) O U)

u)

^ cn

cn

U)

iii o

0^

<r

<i)f-QlUJZC3t-X

Figure

107.

Curves

obtained

by

least

squares

fitting

the

yield

strength

(0.2%

offset)

vs.

the

Rockwell

B

hardness

of

the

2291

-T87*

round

robin

samples

as

measured

by

each

of

the

five

participating

laboratories.
I
NBS>114A inev. »>7«>

U.S. OEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 80-2069

.Gov'L AcLession No. 5«. R«c»atent* i Accession^ Noi.

4. TITLE AND SUBTITLE

Nondestructive Evaluation of Nonuniformities in

2219 Aluminum Alloy Plate - Relationship to

Processing

5. Publication Date December 1980

6. Porforming Organization Coda

7. AUTHORISE |_^ Swartzendruber , L. Ives, W. Boettinger, S. Coriel 1 ).iT^ Ballard, D. Laughlin, R. Clough, F. Biancaniello, P. Blau,

3. Performing Organ. Report No.

10. Project/Task,^orl< Unit No.

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

11. Con tract/ Grant No. Government Order

W-14,637

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS rsrra.r, City, SiMte. ZIP)

National Aeronautics and Space Administration

Washington, DC 20546

13. Type of Report & Period Covered Technical

August 1979 - Sept. 198(1

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FIPS Sofb//are Summary, is attached.

16. ABSTRACT .a 2GO*woni or less (actual summary ot most si^nidcant irtlocmation, U document includes a significant bibliography or

literature surrey, mention it here,J The compositional homogeneity, microstructure , hardness, electrical conductivity and

mechanical properties of 2219 aluminum alloy plates are influenced by the process

variables during casting, forming and thermomechanical treatment.

17, KEY WORDS ( SIX :o r.velve enmea; alphabetical order; capitalize on*/ the (irst letter ot the lirst key word unless a proper name;

separated br ^semicolons)

Agi ng ; e lectrical conductivity; hardness; homogeneity; microstructure;

precipitating; segregation; solidification; thermal mechanical treatment.

13. AVAILABILITY Unlimited 19. SECURITY CLASS

(THIS REPORT)

21. NO. OF

PRINTED PAGES

' For OfficiJl Distribution. Do Not Release to NTIS UNCLASSIFIED

i Oroer From Sun. of Doc.. U.S. Government Printing Office, Washington, DC

20402, SD Stocx No. SN003-0G3-

20. SECURITY CLASS

(THIS PAGE)

22. Price

Orcer “^rom N.itionnl Technical Information Service iNTIS), Sonngfield,

VA. ;3’.G1 UNCLASSIFIED

USCOMM-OC


Iii{iiII]Ii I