bluuebunny/crossref_metadata_2025 huggingface dataset:
Are Hydraulics Holding Their Own?
Authors: Sharpe R. Q. , Henrikson K. G.
Published: August 2009

This question is a challenge to everyone connected with fluid power hydraulics—fluid suppliers, component manufacturers, designers, and research people, as well as users. This seems a good time to examine our present position and to determine whether we are all doing our full share for the future of hydraulic power. World War II triggered a tremendous expansion of the use of fluid power for actuating and controlling mechanisms in a wide range of applications. The metalworking industry rapidly converted many machine functions to hydraulic actuation. An increasing number of large presses, die-casting machines, and similar equipment are being designed to use fluid power. The widespread use of fluid power in aircraft is continuing and is being extended to the guided missile and satellite field. More and more marine equipment, such as steering gear, winches, hoists, and other equipment drives, retractable pilot houses, and automatic hatch-cover equipment, is hydraulically powered. Hydraulic power on agricultural equipment has helped to mechanize the farm. This very substantial and expanding field has generated new pumps and other hydraulic components to meet requirements which differ substantially from the industrial and aircraft fields. Similar to the needs of the farmer are those of the contractor in the construction field where hydraulic control of many items has been very beneficial. Encountered in these fields are problems of low-temperature starting and a wide range of operating temperatures not normally encountered in most industrial applications. Such problems are particularly severe in the aircraft and missile field. This aspect of the use of fluid power will be discussed in further detail later.
A Spray Flammability Test for Hydraulic Fluids
Authors: Rowand H. H.
Published: August 2009

A serious threat to life and property in many industries is the hazard of a pressurized hydraulic line rupturing, causing the escaping fluid to enter the flame of a fuel burner. The test described here simulates this danger and evaluates the fire resistance of hydraulic fluids under such conditions. The most important factor in the test equipment is the provision of a broad range of spray velocities and densities. The spray equipment is described and illustrated, and the test procedure is outlined. Data are presented from tests of one mineral oil, three water-in-oil emulsions, six water-glycol fluids, and nineteen synthetic organic fluids. Selected 35-mm colored slides illustrating the equipment and test conditions were made into black-and-white enlargements for this paper. In this process, much of the contrast was unfortunately lost. Only four synthetic organic fluids failed to ignite under one or more test conditions. All three water-in-oil emulsions tested ignited. However, when the fluid stream is of sufficient density and velocity, a typical mineral-oil hydraulic fluid will not ignite.
High-Temperature Mechanical Properties of Tantalum
Authors: Holden F. C. , Schwartzberg F. R. , Jaffee R. I.
Published: August 2009

Recrystallization, tensile, and creep-rupture behavior of high-purity tantalum and two interstitial-containing tantalum alloys have been determined. After a 75 per cent cold reduction, tantalum was completely recrystallized on annealing 1 hr at 1200 C; this temperature was increased slightly by adding 560 ppm oxygen. Tensile properties up to 500 C were determined. It was shown that the influence of interstitials in causing discontinuous yielding could be correlated with diffusivities. The moderate (25,000 to 32,000 psi) tensile strength of unalloyed tantalum can be increased by cold working and by minor additions of interstitials. The creep resistance of tantalum is increased by interstitial additions at short times and moderate temperatures, but is relatively unaffected at higher temperatures and longer times. Cold work remains effective in strengthening tantalum up to 750 C.
Effect of Oxygen and Nitrogen on Workability and Mechanical Properties of Columbium
Authors: Begley R. T. , France L. L.
Published: August 2009

Currently, considerable effort is being devoted to the development of columbium-base alloys for high-temperature structural applications. Because of its high melting point (2468 C), intermediate density (8.57 g per cu cm), generally good ductility, attractive high-temperature strength, and low ductile-brittle transition range, columbium has considerable potential as a base for high-temperature alloys. One of the difficulties associated with the melting, processing, and application of columbium is its reactivity with atmospheric gases, even at moderately elevated temperatures. The workability and mechanical properties of the metal are seriously affected by the gaseous impurity level. The work described in this paper was undertaken to provide data concerning the effect of oxygen and nitrogen additions on the hardness, workability, strain hardening characteristics, and recrystallization behavior of columbium. The solid solubility of oxygen in columbium is quite high compared to that of most of the other refractory metals. Seybolt [1] reported the primary solid solubility to be 0.25 and 1.0 per cent by weight at 775 and 1100 C respectively. Recent work by Elliott [2] indicates a solubility of 0.25 per cent by weight of oxygen at 500 C, and a maximum solubility of 0.72 per cent by weight at 1915 C. Three oxides, CbO, CbO2, and Cb2O5, exist in the system. A eutectic reaction occurs between the α-columbium primary solid solution and CbO at 10.5 per cent by weight of oxygen and 1915 C. Oxygen has a pronounced effect on the room temperature hardness and tensile properties of columbium. Tottle [3] has reported that increasing the oxygen content of columbium from 0.03 to 0.41 per cent by weight raises the ultimate tensile strength from 41,000 to 131,250 psi, and the hardness from 87 to 331 diamond pyramid hardness. Several investigators [4,5,6] have observed repeated yielding and the return of the yield point on aging in columbium, which are indicative of strain aging. Earlier work by the authors [6] indicated that oxygen was the interstitial element responsible for the observed strain-aging phenomena.
Effect of Purity and Manufacturing Variables on Elevated Temperature Properties of Beryllium
Authors: Beaver W. W. , O'Rourke R. G. , Hurd J. N.
Published: August 2009

The tensile, compressive, and shear properties of beryllium in the temperature range from 800 to 1500 F for various strain rates are evaluated for beryllium of different grain sizes, fabrication characteristics, and oxide contents. Enhanced elevated temperature properties through grain boundary distribution of beryllium oxide in beryllium metal are shown, and the effects of grain size and crystal anisotropy at elevated temperature are discussed. The effects of purity, grain size, and other processing variables on the elevated temperature thermal properties, including thermal conductivity, specific heat, and coefficient of expansion, are also presented. Variations influencing chemical behavior are noted. Comparisons with some low-temperature properties are made to illustrate effects influenced by temperature and those independent of temperature.
Effects of Heat Treatments on the Tensile and Corrosion Properties of Zircaloy 2
Authors: Goodwin J. G. , Rubenstein L. S. , Shubert F. L.
Published: August 2009

The effects of temperature, time at temperature, and cooling rate on the tensile and corrosion properties of Zircaloy 2 were studied. It was found that both tensile and corrosion properties were dependent upon cooling rate and when discussing the other variables, a cooling rate must be specified. In general, above 1700 F the yield strength increased and the ultimate strength decreased. Ductility decreased with increasing heat treatment temperature above 1450 F. Cooling Zircaloy 2 at a rate greater than 90 F per min resulted in satisfactory corrosion resistance, whereas cooling at a rate less than that caused decreased corrosion resistance. Corrosion resistance of slowly cooled material decreased with increasing temperature above 1500 F.
Survey of the Mechanical Properties of Yttrium and Yttrium Alloys
Authors: Carlson O. N. , Bare D. W. , Gibson E. D. , Schmidt F. A.
Published: August 2009

A survey of the mechanical properties of yttrium and the effects of fifteen different elemental impurities and alloying additions on its tensile strength, ductility, and hardness are described. These properties were found to be relatively insensitive to small additions of most of these elements. Factors which influence the mechanical properties of yttrium to the greatest extent are heat treatment, degree of cold working, and grain orientation. Yttrium exhibits an anisotropy of hardness as determined from single crystal studies and strain hardens extensively with a small degree of cold working. Its hardness is quite dependent also upon the thermal history of the specimen.
Columbium and Tantalum Fabrication
Authors: McCullough H. M.
Published: August 2009

There has been a rapid increase in interest in columbium and tantalum for use in nuclear energy, chemical corrosion, and high-temperature applications because of their high melting points, high strengths at elevated temperatures, excellent corrosion resistance, and ease of fabrication. Until a few years ago these metals were laboratory curiosities or were produced only in small quantities for very specialized applications. Their utilization was impeded by the lack of ore reserves and the extreme difficulty in winning the metal from the ore. Today, however, both of these problems appear to have been overcome. Although the metals are still costly, the price for mill products is continuously decreasing as the demand increases. However, since the known potential ore reserves of tantalum are estimated to be one tenth that of columbium it is expected that more columbium will be utilized than tantalum if only for economic reasons. Inasmuch as the fabrication procedures for columbium and tantalum are dependent to a large extent upon the raw material and method of consolidation, a review of these processes is in order before proceeding with fabrication discussions.
Deoxidation and Denitrification Studies of Chromium and the Effect on Low-Temperature Properties
Authors: Levingston H. L. , Grant N. J.
Published: August 2009

The brittle to ductile transition temperature of commercial electrolytic chromium was investigated. Elements with a high affinity for oxygen, nitrogen, and carbon were added to the chromium. The reaction products which formed and their effect on several properties of chromium were correlated with ductility criteria. The investigation showed that the transition temperature of chromium, as determined by three-point bend tests, can be lowered by deoxidation and denitrification techniques as well as by grain size refinement and by testing at reduced strain rates.
Introduction
Authors: Lamar William L.
Published: August 2009

One purpose of this symposium is to sharpen interest in technical development in the handling and utilization of water and industrial waste water. Committee D-19 on Industrial Water and Industrial Waste Water recognizes the challenge of our time to solve problems dealing with quality of water to meet the increasing need. This challenge prescribes that our technical development in the handling and utilization of water be such that it exceeds the rate at which new problems arise from our expanding population and developing complex industry. Technological advancement in the field of water is not an abstract matter for scientists and engineers; it is directly related to the development, or even survival, of our economic way of life. By 1975 it is estimated that our population will be about 235 million, and we must look forward to even greater increases beyond that date. Providing the water supply for this growing population and expanding industry will require exponential efforts as procurement becomes more difficult at locations where water is needed. The situation is made more intractable by the growing population and expanding industry which adversely affect the quality of the receiving waters at a time when many new and improved processes require water of better quality. The conditions and problems that we face in the economic utilization of our water supplies are many-fold. Progress in nuclear chemistry requires adequate means of treatment and disposal of radioactive wastes as well as adequate methods of analysis. More and more development is needed in the disposal of many wastes including new ones from new processes, in the treatment of water to meet specific needs, and in the conservation of water.
Disposal of Industrial Radioactive Waste Waters at Hanford
Authors: Schwendiman L. C. , Brown R. E. , Honstead J. F. , Linderoth C. E. , Pearce D. W.
Published: August 2009

In the fifteen years since the fission process began generating highly radioactive isotopes in large quantities, many methods have been utilized for radioactive waste disposal. In this same interval greater quantities of radioactive wastes have been generated and disposed to the environment or stored in interim containers at Hanford than at any other atomic installation. This experience will be discussed with the objectives of pointing out the present state of our knowledge and practice, and of indicating probable future trends. The problems encountered in handling, storing, and diluting radioactive liquid wastes are similar in many respects to those encountered in other chemical industries. Radioactive waste is, however, unlike other industrial wastes in that physical and chemical processing are of no avail in destroying the toxic property of the waste. It can be transferred from one physical or chemical carrier to another, diluted, and concentrated; but the only process for eliminating the radioactivity is the built-in radioactive decay process itself. It is for this reason that some disposal methods are better referred to as interim storage methods. Radioactive wastes are furthermore unique in that only extremely small concentrations of isotopes may be permitted entry to the body. For example, whereas nonradioactive arsenic can be tolerated to the extent of 0.05 μg per ml in drinking water (1),2 the maximum permissible concentration (MPC) of radioactive arsenic-76 is 3 × 10−9 μg per ml (2). The national interest in disposal of radioactive wastes was highlighted in the Public Hearings on Industrial Radioactive Waste Disposal last January before the special Sub-Committee on Radiation of the Joint Committee on Atomic Energy (3). During these hearings the subject of radioactive waste disposal was reviewed by many representatives from various atomic installations, and by consultants in geology and hydrology. It is generally agreed that safe, economical ways will be found to dispose of all nuclear wastes in the forthcoming era of nuclear power development; however, much research is required. The practices used to date have been helpful guides to future disposal, particularly in regard to low-level wastes.
Improvements in Water Treatment for Once-Through Reactor Cooling
Authors: Richman R. B.
Published: August 2009

Treatment of natural water which has been partly coagulated and settled with minute quantities of any of several new high-molecular-weight organic polymers permits increased flow through modified rapid sand filters. Polymer materials used include acrylamides, polysaccharides, carboxymethylcellulose derivatives, alginates, and carrageenan, among others. The amounts of these materials needed for effective conditioning of the filters are extremely small, dosages ranging at the present time from 0.002 to 0.030 ppm (0.0001 to 0.0015 grains per gal of water). Maximum efficiency is ordinarily obtained by addition of these chemicals to the filter influent flume or directly to the filter gullet. The type of filter system which benefits most from the use of conditioning polymers is a modification of a rapid sand filter. A filter bed composed of 12 in. of gravel, 3 to 6 in. of sand, and 24 to 27 in. of anthracite filter material has given maximum efficiency at Hanford. Sensitive instrumentation is important, and measurement of minute turbidity concentrations is necessary to control film formation in the reactor. At Hanford a light scattering microphotometer has been adapted to measure routinely turbidities in the range 0.001 to 0.010 ppm in the treated water. Increases in water plant capacity and savings in cost have been significant at Hanford with the use of filter conditioning. Total flows through the filters can be 200 per cent greater with filter conditioning than with more conventional treatment methods. A capital cost savings of $250,000 was realized at the time the new treatment was started, and annual cost savings of over $200,000 result from the use of this filter conditioning treatment. The quality of the water produced by this treatment is fully as good as that obtained with previous treatments, and control of water quality is more flexible with filter conditioning.
Operation of Batch-Type and Continuous Electric Membrane Demineralizers
Authors: Katz William E.
Published: August 2009

The electric membrane or “electrodialysis” process for removing excess dissolved salts and minerals from water is rapidly increasing in use—both in the United States and abroad. On January 1, 1958, there were only two production (nonexperimental) electric membrane plants in operation in the United States. Only two years later, eleven plants with a combined capacity of over 350,000 gal per day were in operation, serving almost 10,000 people in Montana, Texas, Alaska, New York State, California, Utah, South Dakota, Arizona, and Illinois. In the Persian Gulf and North Africa (where oil activity is combined with a notable lack of fresh water), the first significant electric membrane installations were erected in 1954. Five years later, approximately twenty plants with an aggregate capacity of some 200,000 gal per day served over 25,000 people with fresh drinking and culinary water in Saudi Arabia, Bahrein, Kuwait, Qatar, Egypt, Libya, Tunisia, and Algeria. This compilation excludes a number of experimental units in this country and abroad; for example, a large plant has been under construction in South Africa for over two years which is designed to produce about 3 million gallons per day.
Solar Distillation of Saline Water with Particular Regard to Materials Problems
Authors: Lappala R. P. , Yaeger L. L. , Bjorksten J. A.
Published: August 2009

A chief factor controlling the practicability of solar distillation of saline water is the total quantity of power potentially available in sunlight. At the latitude of San Francisco, this is 73 million Btu per acre. Accordingly, assuming 100 per cent utilization of sunlight, the maximum amount of water that could possibly be distilled in one acre is 8110 gal per day. This means that for full operation at capacity of 34 tons per day, all sunlight falling on an area of one acre will have to be used. By use of multiple-effect solar stills, re-using the latent heat of vaporization, the yields can be increased, but the cost of the device is also increased. Inasmuch as the yield is fixed by total amount of solar energy available, it becomes necessary to effect the economies required by practical conditions by using the lowest-cost device possible to cover this acre. This means not only the lowest possible cost from the standpoint of initial installation but also from the standpoint of continued maintenance.
High-Energy Radiography in the 6- to 30-Mev Range
Authors: Bly James H. , Burrill E. Alfred
Published: August 2009

The dynamic interest in the radiography of very thick steel sections and solid rocket-propellant motors has become the basis for exploring in detail the radiographic characteristics of high-energy X-rays. Furthermore, new types of particle accelerators capable of producing X-rays in the multi-Mev region have become developed to practicality within the past few years (1–4). These two new factors, combined with the scattered and sketchy information on high-energy radiography in the literature, justify a consolidation of known data, corroboration of theoretical extrapolations, and reporting of new techniques of value in this particular field of radiography. This paper attempts to collect much of the available information of importance in the supervoltage and high-energy radiographic ranges. In addition, it is hoped that this report can form the third part of a series of papers discussing in detail the radiographic characteristics of 0.5 to 2.5-Mev X-rays (5), and of 2-to 6-Mev X-rays (6). The present paper will extend the same lines of reasoning into the 6- to 30-Mev X-ray range. In the 0.5- to 6-Mev range, the Van de Graaff and resonant transformer types of X-ray equipment have been capable of providing the intensity and penetrating power necessary for high-quality radiography in the steel thickness range up to 10 in. Above about 3 Mev, however, and for heavier steel sections, these two direct acceleration methods become impractical for flexible industrial use. In their stead, the betatron and microwave linear electron accelerator (linac) become the radiation producers of greatest practicality.
An Ultrasonic Method to Detect, Count, and Measure Fluid-Contaminating Particles
Authors: Albertson Charles P.
Published: August 2009

Contamination in the fluid systems of aircraft and missiles is analogous to the presence of flaws in the structural members and may be equally dangerous. Service life of many components in modern turbine propulsion and control systems may be severely shortened by particulate contamination of fuels or hydraulic fluids. In fact, certain high-performance airborne systems are reported to be sensitive to the effect of single particles of a few microns in diameter. In recent years great emphasis has been placed on fluid cleanliness and the development of effective filters. Rather elaborate sampling and analysis procedures employing either microscopic sizing and counting or gravimetric methods are often used in the attempt to evaluate system requirements and to minimize the potential hazards of contamination. The need for more efficient and reliable fluid inspection techniques has been generally recognized. Basically, what is most needed is a nondestructive test applicable to dynamic fluid systems which would permit 100 per cent volumetric inspection. A desired objective is the detection, measurement, and counting of subsieve particles having maximum dimensions of 1 to 100 μ, that is indication of particles 4 × 10−5 in. or larger.
Reactor Spectra Considerations in Radiation Effects Predictions
Authors: Romanko J.
Published: August 2009

A brief discussion is given on the specification of reactor differential flux spectra for both neutrons and gamma rays, specifically on the differential flux spectra of a typical light-water-moderated reactor, the Ground Test Reactor. Following this, calculations of displacement production rates in crystalline solids such as metals and semiconductors for various specifications of the neutron flux spectrum are given. Examples are chosen to illustrate the relative importance of the various energy groups of neutrons. The extent of the errors introduced in the calculations, when incorrect specifications of flux spectra are used, is indicated. The importance of specifying differential gamma flux spectra in radiation damage studies concerning organics is stressed briefly.
Introduction
Authors: Perry H. A.
Published: August 2009

The growth in the use of reinforced plastics since World War II has been phenomenal. Materials falling in this category are to be found in industrial equipment, in consumer products, in military devices and in space equipment. Reinforced plastics are now classed as very important materials of construction which figure prominently in the nation's economy. Reinforced plastics have been in use in flight vehicles since the days of doped muslin. At the present time, metal, glass-fiber, and ceramic reinforced plastics are widely used in aircraft. Of particular importance is the widespread use of boroaluminosilicate fibrous glass-reinforced plastics in devices such as radomes, airframes, structural accessories, compressed gas containers, engine housings, helicopter rotor blades, helmets, and many others. Asbestos and aluminum silicate fibers are also employed. Special fibers and resins having higher modulus of elasticity, lower dielectric constant and loss factor, greater strength at normal and elevated temperatures, greater weather resistance, and other special properties are under development. As these improved materials become available commercially, it is expected there will be further exploitation of reinforced plastics in aircraft. Reinforced plastics have been in use in rockets since the invention of rolled paper casings for fireworks. Of great current importance and interest is the fact that the feasibility has been firmly established for the use of boroaluminosilicate fibrous glass-reinforced plastics in the construction of high-pressure solid-propellant motor casings for large rockets. Many final stage rocket motors made of isotensoid-wound glass-roving reinforced plastics have been flown successfully in the exploration of space. No operational failures of these casings have been reported to date. The majority of spent motors still in orbit are made of reinforced plastics.
Evaluation of Reinforced Plastics for High Temperature Structural Applications
Authors: Hribar V. F. , Dowell A. M.
Published: August 2009

When reinforced plastics are exposed only briefly to extremely high temperature, their inherent strength-to-weight characteristics may be effectively utilized in hypersonic vehicle structural applications. This paper presents test methods for the determination of the mechanical and thermal properties of molded reinforced plastics under steady-state conditions and under transient conditions which involve rapid heating and loading at the elevated temperature. Data are presented for a commercial phenolic molding material evaluated by these methods. A statistical analysis is used to determine the spread of the data and the mean strength of the material at temperature. Prediction limits are plotted which allow the designer to interpret the suitability of a material for a given design. Structural tests of a plastic wing designed from the prediction limits prove conclusively that the test method yield valid data for design applications. The tests show that phenolic glass fiber reinforced molding compounds now available can be used to meet current and forseeable requirements of hypersonic vehicles designed for short-term flights.
Evaluation of Reinforcements for Structural Plastics
Authors: Erickson P. W. , Milani V. , Silver I. , Perry H. A.
Published: August 2009

There is still a need for further standardization in the testing of reinforced plastics for structural purposes. Several variables in the preparation and testing of glass-fabric-reinforced test specimens are shown to have a marked effect on the mechanical data obtained. The variation in apparent properties can be as great as 100 per cent. The deficiencies of existing test methods for roving reinforced plastics are discussed. An improved procedure for the fabrication of test specimens containing parallel roving reinforcements, as well as methods for stressing the specimens to determine their flexural properties and horizontal shear strengths, are described. A hydraulic tester for determining the tensile strength and Young's modulus of elasticity of parallel roving-reinforced rings is also described.
Principles and Capabilities of Ablation
Authors: Steurer Wolfgang H.
Published: August 2009

Ablation as a technical term represents the removal of material at the surface which occurs at certain combinations of heat and pressure. At extremely low pressures, as encountered in space technology, surface material may be removed by sublimation at very moderate temperatures as soon as its vapor pressure is approached. In contrast to this “vacuum ablation,” the ablation at atmospheric and higher pressures requires considerable amounts of heat for activation and, consequently, lends itself to heat absorption. The present discussion is concerned exclusively with the latter type of “thermal ablation” and its application in thermal protection systems.
Introduction
Authors: Kinney J. E.
Published: August 2009

How certain are we that the data we use really define water quality adequately and accurately? How often do we compare data from different sources and assume that the analytical methods used were identical? How often in reporting results do we neglect to report the limitations on accuracy and precision of the methods used? How often in the interests of reducing costs (defined as feasibility) do we provide data on long-term composites as an alternate to sampling that will show ranges? How often do we adopt analytical procedures used by regulatory agencies without questioning their validity? How often do we accept published figures as accurate?
Water—Raw Material for Utilities Steam Generation
Authors: Muller A. C.
Published: August 2009

The increasingly high temperatures and pressures used in modern utility steam generation have fostered a need for (1) high-purity water for boiler feed, (2) more sensitive tests to determine minute amounts of materials, and (3) higher frequency of tests to follow changing conditions more completely. This paper describes current testing methods and equipment, with emphasis on automation as applied to continuous analysis. It points out the difficulties in obtaining representative samples because of possible extraneous contamination and the presence of particulate matter in the stream.
Continuous Automatic Boiler Water Silica Analysis
Authors: Allen R. C.
Published: August 2009

Since higher pressure boilers demand lower boiler water silica concentrations to ensure the minimum silica carry-over in the steam, constant manual sampling and analysis are necessary. The silica limit for the 2000-psi boilers at the Los Angeles Department of Water and Power Scattergood and Valley steam plants is 1.0 ppm. The limit for the main steam is 0.02 ppm silica. The normal laboratory hand method consumes about 30 min for a silica determination. However, in most instances, when a generating unit is returned to service in the early morning hours with expectation of being at full load by 8 a.m., the silica concentration usually rises above normal. This is a period when there is no laboratory coverage, and the assignment of an operating assistant to make these tests is not practical. Some means of continuous automatic sampling and analysis was sought to assist the operating personnel in returning a unit to service and raising boiler pressure and load in accordance with a curve relating boiler pressure to silica concentration. After investigating several of the various types of silica analyzers on the market, the Department of Water and Power purchased an instrument in November 1960. The instrument is mounted on a collapsible cart making it completely portable. It has been used with good results at the Valley and Scattergood steam plants. It is also expected to see service during the start-up of the units at the new Haynes plant. The test method used is a modification of ASTM Method D 1689 — 59 T using the 1-amino 2-napthol 4-sulfonic acid reduction of the yellow silico molybdic acid forming molybdenum blue. However, since the samples are much smaller than the normal hand sample, the reagent concentrations are reduced (see Fig. 1). To minimize the precipitation of ammonium molybdate in the tubing, the amount used is reduced to 10 g per liter. The amino napthol sulfonic acid solution is diluted 1 to 10 before use. Five per cent oxalic acid instead of the usual 10 per cent is used. In an effort to eliminate the use of the poisonous oxalic acid, both citric and tartaric acids have been tested. No difference in the test results was found. However, both of these acids tend to form a mold or fungus growth within a short time, and small pieces could plug the tubing in the system. The use of oxalic acid was reinstituted. The three 4-liter reagent bottles are carried on the cart, and this amount is sufficient for two days of continuous operation.
Introduction
Authors: Banerjee B. R.
Published: August 2009

This sixth volume on “Advances in Electron Metallography” continues the fine tradition of its predecessors in providing a continuing record of advances in the fields of electron microscopy and electron probe X-ray microanalysis. The progressively increasing range of subject matter and coverage of these volumes reflects the broadening interests and scope of Subcommittee XI of Committee E-4. Indeed, recognizing this transition, a new name for Subcommittee XI, “Electron Microscopy, Diffraction, and Microprobe Analysis,” was approved by the executive committee of E-4 at the Sixty-eighth Annual Meeting. The first paper, by Gilpin et al, describes an electron microautoradiographic technique, which was developed to study the microscopic distribution of a radioactive isotope in steel specimens by electron microscopic examination of a gelled emulsion monolayer containing fine silver bromide particles. The resolution of the technique was estimated at about 0.1µ. Using tritium, H3, hydrogen migration through AISI 4340 steel was studied. The results surprisingly suggest that, though pronounced cathodic reaction occurs at the prior austenite boundaries, the volume migration is random and not through these boundaries. Under tensile stress, a hydrogen-charged specimen exhibited hydrogen migration to the region of maximum stress triaxiality. Phillips compares electron metallographic techniques with light microscopic and interferometric methods for study of slip line spacing and heights in a copper alloy with about 3 per cent cobalt. The electron metallographic methods (both replication and thin section) were found to have better resolution—especially in lateral resolution of slip line spacing—than light interferometry. Transmission techniques showed slip line spacings as small as 300 A; a new technique for gaining improved contrast at slip steps involved metal-shadow casting a one-sided thinned transmission specimen. The slip-step spacing and height in the aged alloy (precipitate size about 180 A) were similar to those in the solution-treated condition. Since dislocations easily penetrated the precipitate particles, this result is not surprising and suggests that precipitation hardening in this alloy is mainly due to coherency strain fields.
A Metallographic Study of the Tensile Deformation of a Copper 3.12 Per Cent Cobalt Alloy
Authors: Phillips V. A.
Published: August 2009

The effect of precipitates on the tensile deformation (2 per cent strain) of a polycrystalline Cu-3.12Co alloy was studied. Deformation was inhomogeneous on an electron microscopical scale as well as on an optical microscopical scale. It was confined to widely separated slip planes or groups of planes. The surface slip topography was studied by light microscopy, 2-beam interferometry, 1-stage and 2-stage replication, and by transmission electron microscopy using 1-sided thinning, including a novel shadow-cast variation. Fine slip, with step heights down to 70 A and spacings down to 300 A, was observed by transmission electron microscopy. Neither the step height nor the step spacings were appreciably altered by the precipitation of coherent spherical cobalt particles with average diameters of up to 180 A. There was some evidence of the dissociation of dislocations and the pinning of the partials by particles. The work hardening rate was affected very little by the presence of particles.
Specimen Carburization by Electron-Beam Contamination
Authors: Szirmae A.
Published: August 2009

Carburization of iron specimens by contamination from the electron microscope had previously been observed. In more recent experiments, carburization did not occur. The difference in behavior was traced to a difference in the pump oil used. These results support the view that the diffusion pump oil is an important source of contamination in the electron microscope.
A Laser Heating Device for Metallographic Studies
Authors: Speich G. R. , Szirmae A. , Fisher R. M.
Published: August 2009

Using an optically pumped ruby laser for a heat source and a helium-water vapor quench, thin metallic specimens can be heated at a rate of 106 C/sec and cooled at a rate of 105 C/sec. An electronic timing circuit controls time spent at a temperature so that heating times as short as 0.001 sec are possible. The temperature reached is determined by the energy of the laser pulse, specimen reflectivity, and thickness. Oxidation of iron surface effectively reduces reflection and, thus, increases energy absorption. Temperature distribution across sections of the specimens is a function of density and thermal diffusivity. For an 0.002-in. iron specimen, front and back temperatures remain nearly equal during heating. Applications of the technique included in this paper are: studies of recrystallization and phase transformation of pure iron, dissolution of pearlite and spheroidite in a eutectoid iron-carbon alloy, and melting and solidification of gold.
Aging Kinetics in 300-Grade Marage Steel
Authors: Banerjee B. R. , Capenos J. M. , Hauser J. J.
Published: August 2009

The relation of fine structure of an 18Ni 300 maraging steel to mechanical properties and fracture toughness was investigated. Sheet specimens were annealed by 1500 F austenizing for 1 hr followed by air cooling to room temperature. Some specimens were aged at 900 F for various times, while other specimens were aged for 1 hr at temperatures from 300 to 1300 F. Microstructure was studied by replication and by transmission electron microscopy. Aging kinetics at 900 F were very rapid; nearly 90 per cent of maximum strength was attained after 1 hr exposure. Between room temperature and 900 F, microstructure changed from a precipitate free blocky martensite to one that had a finely dispersed precipitate throughout the martensite structure. At higher temperatures than 900 F overaging caused a decrease in toughness. Strength and hardness increased rapidly from 400 to 1000 F. The precipitate was identified as Ni3Mo with possibly some Ni3Ti also present. The effect of test temperature on fracture toughness was evaluated at temperatures from +100 to −320 F. A distinct ductile-brittle transition occurred between −100 and −320 F. Fracture toughness decreased from a room-temperature value of 212 ksi √in. to 50 ksi √in at −320 F.
Elevated-Temperature Static and Dynamic Sea-Salt Stress Cracking of Titanium Alloys
Authors: Turley R. V. , Avery C. H.
Published: August 2009

Titanium alloys 6Al-4V, 8Al-1Mo-1V, 4Al-3Mo-1V, 5Al-2.5Sn, and RS-140 were evaluated for susceptibility to elevated-temperature static and dynamic sea-salt stress cracking to determine the most promising alloys for application to advanced aircraft. The nature of this cracking was also studied for evidence that would reveal the fundamental mechanisms involved. All alloys were susceptible to stress-corrosion cracking, and the susceptibility was increased with elevated temperature. Alloy 4Al-3Mo-1V was the most resistant, and 5Al-2.5Sn was least resistant. Alloy 8Al-1Mo-1V was the only one susceptible to corrosion fatigue. Fatigue precracks, anodizing, thickness, and grain direction had little or no effect on stress-corrosion susceptibility. Welding and stress relieving increased the stress-corrosion susceptibility. Cracks initiated and propagated from corrosion grooving at grain boundaries and transgranular crystallographic planes without relating to pitting, roughness, or other surface irregularities. Extended research to reveal mechanisms operative during stress corrosion of titanium is recommended as a means of understanding the factors which reduce or increase resistance to stress-corrosion cracking.
The Relative Stress-Corrosion Susceptibility of Titanium Alloys in the Presence of Hot Salt
Authors: Piper D. E. , Fager D. N.
Published: August 2009

Steady-state stress-corrosion tests at elevated temperature were performed on three titanium alloys. Mill annealed titanium 6Al-4V was the least susceptible, followed in order of increasing susceptibility by titanium 8Al-1Mo-1V and titanium 6Al-6V-2Sn. Sodium chloride was more detrimental than ASTM synthetic salt. Extensive tests were conducted on duplex annealed titanium 8Al-1Mo-1V. Cyclic state testing of this alloy indicated an absence of stress-corrosion cracking and demonstrated that the time at temperature below the maximum operating temperature of a supersonic aircraft might be an important variable. Exposure tests on brake-formed, stress-relieved titanium 8Al-1Mo-1V sheet specimens indicated a deteriorating effect distinct from stress-corrosion cracking. Fatigue crack growth and fracture toughness determinations indicated no embrittling effects in titanium 8Al-1Mo-1V exposed to hot salt in the absence of stress.
Investigation of Long-Term Exposure Effects Under Stress of Two Titanium Structural Alloys
Authors: Martin George
Published: August 2009

Notched and unnotched sheet specimens of two titanium alloys, Ti-6Al-4V and Ti-8Al-1Mo-1V, were exposed at 650 F and stressed by a cantilever arrangement to 25 to 30 per cent of their yield stress. Specimens were tested for periods up to 20,000 hr as received, coated with salt, coated with a silver brazing alloy, and coated with a silver brazing alloy and salt. A fifth set was prepared like the last but was exposed cyclically to furnace atmosphere for two-week periods and then in a humidity cabinet at 100 F for two weeks. Specimens were studied by optical microscopy, electron microscopy, and X-ray diffraction. Electron microscopy indicates that cracking is primarily intergranular, but transgranular cracks are possible. X-ray diffraction studies show that titanium chloride and sodium titanate are absent from the corrosion products. Silver braze coatings cause rapid surface deterioration. There is a complete loss of adhesion between braze and parent material after a few thousand hours exposure.
Effects of Environment on Cracking in Titanium Alloys
Authors: Hatch A. J. , Rosenberg H. W. , Erbin E. F.
Published: August 2009

The laboratory conditions under which hot-salt cracking can occur in titanium alloys are reviewed and orders of merit among the alloys established. The large differences among alloys give promise of new alloys immune to the phenomenon. Hot-salt cracking is a case of classical stress corrosion. Alloy research and development disclose a system of titanium alloys that is immune to hot-salt cracking. One promising composition, Ti-2Al-4Zr-4Mo, is shown to have excellent combinations of mechanical properties. The fracture toughness of commercial titanium alloys in salt water is also examined. In the presence of fatigue cracks actively extending under applied loads, salt water can have the effect of reducing the crack propagation resistance of several titanium alloys. Because salt water has no effects on titanium alloys in the absence of cracks, its environmental effect is not classical stress corrosion. The problem can be largely eliminated in Ti-8Al-1Mo-1V sheet by creating microstructures consisting of a continuous matrix of transformed beta.
Basic Mechanisms of Stress-Corrosion Cracking of Titanium
Authors: Rideout S. P. , Louthan M. R. , Selby C. L.
Published: August 2009

Prepolished strips of Ti-8Al-1Mo-1V, stressed to the yield point at 650 F, cracked when exposed to either chloride, iodide, or bromide salts. Cracking was most severe in specimens exposed to pure sodium chloride (NaCl). Chemical analyses of corrosion products formed by NaCl exposures showed that aluminum was preferentially attacked. Autoradiographic techniques with radiotracers H3, Cl36, and Na22 were used to study the distribution of those elements in salt-coated specimens, and the results suggested that hydrochloric acid (HCl) and sodium hydroxide (NaOH) were produced by salt-metal-water reactions. Specimens exposed to HCl gas alone cracked within short times, but no cracking was produced by NaOH exposures. Experimental results can be interpreted to support the hypothesis that hot-salt cracking occurs by hydrogen embrittlement.
An Investigation of Stress-Corrosion Failures in Titanium Compressor Components
Authors: Duttweiler R. E. , Wagner R. R. , Antony K. C.
Published: August 2009

The cracking of J93 jet engine components manufactured from Ti-7Al-4Mo and Ti-5Al-2.5Sn was shown to result from silver chloride stress corrosion. Laboratory testing was conducted to demonstrate the effect of intimate contact between titanium alloys and silver and silver chloride. An investigation of the mechanism of attack suggested that the deleterious effects noted were the result of silver's unique ability to react with, and thereby concentrate minute amounts of chlorine such as might prevail in a test environment. Because of this behavior, silver plate was removed from all areas in the J93 engine where it came in intimate contact with titanium components.
Salt Stress Corrosion of Ti-8Al-1Mo-1V Alloy Sheet at Elevated Temperatures
Authors: Heimerl G. J. , Braski D. N. , Royster D. M. , Dexter H. B.
Published: August 2009

Many small self-stressed and residual-stress specimens were coated with salt, exposed up to 6400 hr at 400 to 600 F, and tested in compression and bending at room temperature to determine the stress corrosion cracking. Of the various salts, sodium chloride (NaCl) was the most corrosive, and thin coatings were more damaging than thick. A decrease in oxygen and air pressure reduced stress corrosion, but the role of moisture and air velocity is still in doubt. Short thermal cycles of 2 or 4 hr from room temperature to 550 F produced less corrosion. Titanium dichloride (TiCl2) was identified as a corrosion product, but the corrosion mechanism is unknown. Surface treatments, such as shot peening, nickel plating, vibratory cleaning, and polyimide coatings, prevented corrosion up to 2000 hr at 600 F.
Functional Man in Simulated Space
Authors: Sullivan A. F.
Published: August 2009

To date, manned operations in space chambers have been restricted to mission testing, and man's unique capabilities have not been usefully employed. Man has not functioned as an in situ experimenter or operator because of the well-recognized physiological restrictions imposed by the available space suits. The early “hard-suit” applied the principle of constant volume to obtain mobility in a pressurized joint. This principle has been further refined and embodied in a space suit developed for NASA. With reduced bulk and weight, and mobility approaching that of an unsuited man, this most recent suit permits immediate consideration of useful manned operations. With further development in the direction indicated by this approach, such operations can reasonably be expected to become routine.