This report presents information dealing with the oxidation of nickel- and cobalt-base superalloys. All of the superalloys will oxidize at high temperatures when oxygen is present in the enveloping atmosphere. The rate of oxidation depends upon alloy composition, temperature, oxygen concentration, oxides formed, diffusion rates of the metals in both base metal and oxide, diffusion rate of oxygen in the oxide, solubility of oxygen in the matrix, and a host of other variables. The effects of oxidation can be beneficial or they can be harmful. The first section of this report deals with the fundamentals of the oxidation of Ni-Cr and Co-Cr alloys. Subsequent sections discuss general surface oxidation, intergranular oxidation, other subsurface oxidation, and the effect of stress on the rate of oxidation. Numerous specific alloys are mentioned in the report; as an aid to the reader, the appendix contains an alloy index of the alloys mentioned in the report along with the compositions of the alloys, and the pages on which mention of the alloys is made.

Premium-quality castings are those which are guaranteed to show a specified high level of mechanical properties. The properties currently being achieved represent significant improvements over those which can be achieved in conventional aluminum-alloy castings and approach the properties currently obtainable in wrought aluminum alloys. These property advances are largely the result of improved casting technique and design. These castings are gradually finding acceptance and usage in aerospace applications, thanks to integrated efforts between the casting producers and their customers. (Author).

This report gives the experiences of several steel producers and consumers with vacuum degassing as a melting practice in the manufacture of high-strength steels for critical applications. The parameters involved in determining the effects of melting practice on mechanical properties are outlined. Pertinent melting processes are described and evaluated qualitatively. In presenting the data, vacuum degassing is compared with other melting practices such as conventional air melting and consumable-electrode vacuum-arc remelting (CEVAR). Generally, there is a trend indicating that vacuum degassing is being used in some production applications instead of air-melted or CEVAR material. In terms of higher and more uniform transverse tensile properties and impact strength, longer fatigue life, and improved cleanliness, the CEVAR alloys were the best. Vacuum degassing by any of the various methods resulted in an improvement in properties of air-melted alloys. In some instances it appeared that the quality of CEVAR alloys could be approached when stream degassing or D-H (Dortmund-Horder) treatment was applied to air melts. Recommendations are given for additional investigations on the effects of melting practice on mechanical properties of premium-quality steels. (Author).

Since the combination of tensile properties and toughness that can be obtained with the maraging steels is higher than can be achieved with other steels by simple heat treatments, there is considerable interest in using the maraging steels for critical components such as rocket motor cases, pressure vessels, and aircraft forgings. This report includes information on the tensile, compressive, shear, bearing, dynamic modulus, impact, bend, fatigue, creep, and rupture properties of the 18 per cent nickel maraging steels and on the effect of temperature on these properties. Data for the properties of sheet, bar, and forgings, as well as data illustrating the effect of cold rolling, variation in the heat treatment, and elevated-temperature exposure also are presented. Data on the effect of specimen orientation, which are also included, indicate that the ductility and toughness of specimens designed to evaluate the properties in the short transverse direction are somewhat lower than in the other directions. The high strength and toughness that can be obtained in the 18 per cent nickel maraging steels make them attractive for certain critical applications that require these properties. The fabrication characteristics, weldability, and simple heat treatment are other advantages of these steels. (Author).

Advances in Space Science and Technology, Volume 8 presents the possibility that what is recognized as lunar cratering was caused by endogenous, volcanic activity rather than by the more widely accepted meteoritic impact mechanism. This book provides an introduction to the technology of rocketry. Organized into four chapters, this volume begins with an overview of lunar volcanism and the interpretation of the widespread phenomenon of cratering. This text then provides a comprehensive examination of one of the major components of the solid propellant rocket. Other chapters consider the many problems associated with design, construction, and testing of motor cases of the solid propellant rocket. This book presents as well a thorough examination of interplanetary mission planning covering such vital elements as the process of mission decision making based on model theory. The final chapter deals with the exploration of the planet Mars. This book is a valuable resource for geoscientists, astronomers, and geologists.

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).

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Volume 3 helps you and your production team use new materials, choose the most efficient surface and edge preparation techniques, and apply coatings that enhance the appearance and performance of your final product. You'll use this book to analyze the machinability, formability and weldability of your materials, and to help assess heat treatment systems, coating processes and materials, application and curing methods, and more.