NATIONAL BUREAU OF STANDARDS REPORT

9909

IMPACT PROPERTIES OF ALUMINUM ALLOY - BETA

SILICON CARBIDE WHISKER COMPOSITES

To

Melpar, Inc. (USAF Contract No. F 336 1 5-68 - C- 106 4)

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards’ was established by an act of Congress March 3,

1901. Today, in addition to serving as the Nation’s central measurement laboratory,

the Bureau is a principal focal point in the Federal Government for assuring maximum application of the physical and engineering sciences to the advancement of technology in industry and commerce. To this end the Bureau conducts research and

provides central national services in three broad program areas and provides central national services in a fourth. These are: (1) basic measurements and standards,

(2) materials measurements and standards, (3) technological measurements and

standards, and (4) transfer of technology.

The Bureau comprises the Institute for Basic Standards, the Institute for Materials

Research, the Institute for Applied Technology, and the Center for Radiation Research.

THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the

United States of a complete and consistent system of physical measurement, coor- dinates that system with the measurement systems of other nations, and furnishes

essential services leading to accurate and uniform physical measurements throughout

the Nation’s scientific community, industry, and commerce. The Institute consists

of an Office of Standard Reference Data and a group of divisions organized by the

following areas of science and engineering

Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic Physics—Cryogenics2—Radio Physics2—Radio Engineering2—-Astrophysics2—Time

and Frequency.2 THE INSTITUTE FOR MATERIALS RESEARCH conducts materials research leading to methods, standards of measurement, and data needed by industry, commerce,

educational institutions, and government. The Institute also provides advisory and

research services to other government agencies. The Institute consists of an Office of

Standard Reference Materials and a group of divisions organized by the following areas of materials research:

Analytical Chemistry—Polymers—Metallurgy — Inorganic Materials — Physical

Chemistry.

THE INSTITUTE FOR APPLIED TECHNOLOGY provides for the creation of appropriate opportunities for the use and application of technology within the Federal Government and within the civilian sector of American industry. The primary functions

of the Institute may be broadly classified as programs relating to technological meas- urements and standards and techniques for the transfer of technology. The Institute

consists of a Clearinghouse for Scientific and Technical Information,3 a Center for

Computer Sciences and Technology, and a group of technical divisions and offices organized by the following fields of technology:

Building Research—Electronic Instrumentation — Technical Analysis — Product

Evaluation—Invention and Innovation— Weights and Measures —* Engineering

Standards—Vehicle Systems Research.

THE CENTER FOR RADIATION RESEARCH engages in research, measurement,

and application of radiation to the solution of Bureau mission problems and the

problems of other agencies and institutions. The Center for Radiation Research consists of the following divisions:

Reactor Radiation—-Linac Radiation—Applied Radiation—Nuclear Radiation.

1 Headquarters and Laboratories at Gaithersburg, Maryland, unless otherwise noted ; mailing address Washington, D. C. 20234.

2 Located at Boulder, Colorado 80302.

3 Located at 5285 Port Royal Road, Springfield, Virginia 22161.
NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

3120625 9909

(Test No. 196180)

IMPACT PROPERTIES OF ALUMINUM ALLOY - BETA

SILICON CARBIDE WHISKER COMPOSITES

By

I. J. Feinberg

Engineering Metallurgy Section

Metallurgy Division

To

Melpar, Inc. (USAF Contract No. F336 1 5 -6 8- C - 1 0 6 4)

IMPORTANT NOTICE NATIONAL BUREAU OF STAN

for use within the Government. Be and review. For this reason, the pi whole or in part, is not authorizer Bureau of Standards, Washington, I

the Report has been specifically pre

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015

accounting documents intended

Djected to additional evaluation

iting of this Report, either in

iff ice of the Director, National

le Government agency for which

2s for its own use. <NBS>

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
j,

HR

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Impact Properties of Aluminum Alloy - Beta

Silicon Carbide Whisker Composites

Hater i a 1 : Thirty-one subsize Charpy V-notch impact test specimens were submitted by the Materials Laboratory, Melpar, Incorporated

for tests. The test material included specimens machined from

extruded 2024, 6065, and 7075 aluminum alloy blanks and specimens

machined from extruded 2024, 6065, and 7075 aluminum alloy - silicon carbide composites.

Test Specimens : Figure 1 shows the configuration of the subsize

impact test specimen and contains pertinent dimensions.

Test Procedure and Equipment ; All specimens were conditioned at room temperature (j0° F) for at least one-half hour before testing

They were broken in a Baldwin 2 foot pound capacity impact tester.

This machine has a C-type pendulum. The striker is rounded to a radius of 0.125 inches and the points of specimen support are 1,78

inches apart. Figure 2 is a view of the impact tester with a test

specimen in place for testing.

Test Resul ts : Table 1 gives the test results.

p -

Table 1„ Charpy Impact Properties of Aluminum Alloy

Blanks and Aluminum Alloy - Beta Silicon

Carbide Whisker Composites

Mel par Specimen

I dent i f i ca t i on Energy

Absorbed Remarks

Foot Pounds

A 1 2024 Blanks, 1HTB 31

Spec, i 0.250

2 .235

3 .256

4 .236

Avg. .244

A1 2024 Composites,

Spec. 1 2

3

4

Avg.

VHTL 42

0.017

.017

.019 Some cladding

.015

.017

Alloy 889 ( A 1 97 1/2$ - Si 2 1/2$) Blanks

Spec. 1 0.572

2 .531

3 .527

4 .606

Avg. .559

Alloy 889 (A 1 97 1/2$ - Si 2

Spec. I 2

3

Avg.

1/2$) Composites, VSSL ^3

0.0440

.O 38O 0.121 In. notch depth,

0.151 In. square.

.0320 0.115 In. notch depth,

0.143 In. square

.

.0380

Alloy 889 ( A 1 97

Spec. 1 OCL.

1 /2$

3

Avg.

Si 2 1/2$) Composites, VSSM 44

0.027

.026

.031

.028

- 3

-

Table 1 . Cont i nued

Melpar Specimen Energy

I dent i f i cat i on Absorbed

Foot Pounds

A1 7075 Composites, VHT8 32

Spec. A

BC

DAvg.

A1 6o6l Composites, VHTM 45

Spec. 1 OC.3

4

5

Avg.

0.250

.190

.255

.238

.233

0.027

.027

.030

.031

.033

.030

A I 7075 Composites, VHTL 4l

Spec . A 0.017

B .016

c .005

D .018

Avg. .014

Remarks

Rema r ks : With only one exception, specimen C, A1 7075 Composite,

VHTlTT, test results showed little scatter. Shear lips

indicative of good ductility were observed on the fracture

surfaces of all of the aluminum alloy blank specimens. The

fracture surfaces of the composite specimens were generally flat

indicating embrittlement.

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