The Physical Metallurgy of Cobalt-base Superalloys
The Physical Metallurgy of Cobalt-base Superalloys

Author: H J Wagner

Publisher:

Published: 1962

Total Pages: 102

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A detailed picture is presented of the physical and chemical phenomena that affect the behavior of cobalt-base superalloys. Solid-solution strengthening is obtained from the high-melting metallic elements molybdenum, tungsten, tantalum, and columbium. These elements also participate in precipitation reactions involving their carbides. Precipitation of intermetallic compounds such as Ni3Ti is an important process in cobalt alloys containing appreciable amounts of nickel and titanium. The relationships among microstructure, heat treatment, and mechanical properties of the important commercial alloys are considered, and whenever possible, explained on the basis of the physical and chem cal processes that occur. (Author).

The Effect of Nuclear Radiation on Structural Metals
The Effect of Nuclear Radiation on Structural Metals

Author: Frederic R. Shober

Publisher:

Published: 1961

Total Pages: 120

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The effect of fast-neutron (>1 Mev) irradiation on the mechanical properties of structural metals and alloys was studied. Although the yield strengths and ultimate tensile strengths are increased su stantially for most materials, the ductility suffers severe decreases. This report presents these changes in properties of several structural metals for a number of neutron exposures within the 1.0 x 10 to the 18th power to 5.0 x 10 to the 21st power n/sq cm range. Data summarizing these effects on several classes of materials such as carbon steels, low-alloy steels, stainless steels, Zr-base alloys, ni-base alloys, Al-base alloys, and Ta are given. Additional data which show the influence f irradiation temperatures and of post-irradiation annealing on the radiation-induced property changes are also given and discussed. Increases as great as 175% in yield strength, 100% in ultimate strength, and decreases of 80% in total elongation are reported for fast-neutron exposures as great as 5 10 to the 21st power n/sq cm. (Author).

Beryllium for Structural Applications
Beryllium for Structural Applications

Author: Webster Hodge

Publisher:

Published: 1962

Total Pages: 230

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Reports of Government-supported research on the physical and process metallurgy of beryllium that were received at DMIC during the period 1958-1960, inclusive, are summarized, together with some reports and publications of foreign authors. No proprietary or classified information is included. In addition, reference is made to some of the more importa t writings on health hazards and safety procedures that appeared during the period covered. (Author).

The Effect of Molten Alkali Metals on Containment Metals and Alloys at High Temperatures
The Effect of Molten Alkali Metals on Containment Metals and Alloys at High Temperatures

Author: M. F. Amateau

Publisher:

Published: 1962

Total Pages: 68

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Corrosion of containment materials is the most serious problem in liquid-metal systems. Most high-temperature engineering metals such as refractory metals, nickel-base and cobalt-base superalloys, and the austenitic and ferritic stainless steels are sufficiently resistant to liquid sodium and NaK to be useful up to about 1600 F. The most important factor in the corrosion of these materials under given conditions of temperature and flow rate is the oxygen content of the sodium. No material is truly corrosion resistant to lithium, although the refractory metals tantalum, columbium, and molybdenum do have some potential for high-temperature service in engineering applications. Zirconium and pure iron may also find some limited use in lithium, especially in lower temperature, twocomponent, static systems. The cobalt- and nickel-base alloys are unsuitable for high-temperature service in liquid lithium. The nitrogen content of the lithium is a particularly important factor. Potassium, rubidium, and cesium are somewhat less corrosive than the other alkali metals. The refractory metals and alloys are little affected by these liquid metals. The sliding and bearing properties of metals are generally affected adversely by the presence of pure molten metals. (Author).

Statistical Analysis of Tensile Properties of Heat-treated Ti-4A1-3Mo-1V and Ti-2.5A1-16V Sheet
Statistical Analysis of Tensile Properties of Heat-treated Ti-4A1-3Mo-1V and Ti-2.5A1-16V Sheet

Author: G. H Beatty

Publisher:

Published: 1961

Total Pages: 54

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IN THE SOLUTION TREATED AND AGED CONDITION, Ti4Al-3Mo-1V has a higher ultimate strength than does Ti-2.5Al-16V, but the two alloys are about even in yield strength and elongation. In the solution-treated condition, Ti-4Al-3Mo-1V is unquestionably stronger than Ti-2.5Al-16V. These conclusions are independent of producer. There is not much difference in the same alloy produced by different companies. The alloys developed under the Titanium-Alloy Sheet-Rolling Program would not endure the most critical interpretation of release property specifications. On the other hand, these alloys come reasonably close to specifications. A complete set of release property specifications is available only for specimens that have been solution treated and aged. Such specimens do not all exhibit the desired ultimate and yield strength, but the percentage of rejects is small enough to be encouraging. (Author).

Department of Defense Refractory Metals Sheet-rolling Program
Department of Defense Refractory Metals Sheet-rolling Program

Author: H. R. Ogden

Publisher:

Published: 1961

Total Pages: 44

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A summary is presented of the status of the Department of Defense Refractory Metals SheetRolling Program to accelerate the development of production techniques for high-quality, consistent sheet products from the refractory metals (Nb, Mo, Ta, and W) and their alloys. The program includes: (1) development of sheet production techniques, (2) establishment of minimum data re uired to evaluate mill production, (3) evaluation of fabrication characteristics of the sheet produced, and (4) establishment of design data. Contracts were awarded for the development of sheet production techniques for all four refractory metals. One contract was awarded for the evaluation of Mo alloy sheet fabrication characteristics. (Author).