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).

The Effect of Fabrication History and Microstructure on the Mechanical Properties of Refractory Metals and Alloys
The Effect of Fabrication History and Microstructure on the Mechanical Properties of Refractory Metals and Alloys

Author: Albert G. Imgram

Publisher:

Published: 1963

Total Pages: 80

ISBN-13:

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This report summarizes the present knowledge concerning the relationship among fabrication history, metallurgical structure, and the mechanical properites of the refractory metals columbium, tantalum, bolybdenum, and tungsten, and their alloys. These are the refractory metals currently reveiveing the most attention for aerospace applications, and are therefore the materials considered in this survey. The report is organized into three main sections, titled ''Fabrication'', ''Microstructure and Alloying'', and ''Interstitial Impurities''. The data presented were selected as those which best illustrate the topics discussed. Descriptions of the metaljurgical principles involved are included. Suggestions for optimizing mechanical properties by controlling metallurgical structure are made where possible. (Author).

The Application of High Pressure in Metal-deformation Processing
The Application of High Pressure in Metal-deformation Processing

Author: F. W. Boulger

Publisher:

Published: 1964

Total Pages: 82

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On October 3, 1963, a symposium was sponsored by the Bureau of Naval Weapons, Metalworking Processes and Equipment Program, on the application of high pressure in metal-deformation processing. Past research has shown that superimposed hydrostatic pressure can significantly increase the ductility at fracture of various materials. These observations have stimulated considerable interest in applying this hydrostatic-pressure effect to metal deformation processing, where it was anticipated that improved ductility and fabricability of brittle materials could be realized. Hydrostatic extrusion and hydrodynamic compressive forging were two such fabrication techniques discussed at the symposium, and preliminary results were found to be encouraging. Another fabrication process that will be investigated in the near future is sheet drawing, where the effect of superimposed pressure improves the ductility to fracture, it was noted that pressure cycling did not improve either the strength or ductility of steels containing various amounts of carbon. In addition to the mechanical-property effects, hydrostatic pressure has been found to affect measurably, numerous metallurgical properties of metals and alloys. (Author).

The Application of Ultrasonic Energy in the Deformation of Metals
The Application of Ultrasonic Energy in the Deformation of Metals

Author: Alan R. Rosenfield

Publisher:

Published: 1963

Total Pages: 88

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On June 21 a symposium was sponsored by the Bureau of Naval Weapons on the application of ultrasonic energy in the deformation of metals. At this session, a number of investigators actively working in the field reported informally on the results of their research. The reports revealed that the results achieved by incorporating ultrasonic transducers into conventional metalforming and-cutting operations are sufficiently promising that the technique merits further attention. Data are available to indicate that application of ultrasonic vibrations during metal working can increase speeds, lower forces, and improve surface finishes. All of these results have been obtained without any observed difference in properties between ultrasonically and conventionally fabricated parts. (Author).

The Engineering Properties of Tungsten and Tungsten Alloys
The Engineering Properties of Tungsten and Tungsten Alloys

Author: F. F. Schmidt

Publisher:

Published: 1963

Total Pages: 154

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The results of a state-of-the-art survey covering tungsten and ten of its alloys are presented. All data are given in tabular and graphical form covering some of the more important physical, mechanical, and metallurgical properties for each material. References are given at the conclusion of each material section.