Composites for aeropropulsion
Report summarizes status of composite materials for aeropropulsion. It describes key advances made in past several years and lists 47 references published from 1971 to 1979.
Engineering topics
Publications and source records attributed to Ault, G. M..
Report summarizes status of composite materials for aeropropulsion. It describes key advances made in past several years and lists 47 references published from 1971 to 1979.
The paper deals with applying composites to the cold- and hot-section components of aircraft turbine engines and analyzing composite structures. The primary experience to date has been with graphite-epoxy materials. The emerging new composites based on fabricable polyimides will find application in components that can operate at temperatures higher than the 350 F allowed by the epoxies. Further major benefits would result if the fiber-reinforced polymer composites could be used for key rotating components, such as the fans of large high-bypass-ratio engines. For the very critical hot turbine components, fiber-reinforced superalloys for turbine blades are considered.
Advanced materials, coatings, and cooling technology is assessed in terms of improved aircraft turbine engine performance. High cycle operating temperatures, lighter structural components, and adequate resistance to the various environmental factors associated with aircraft gas turbine engines are among the factors considered. Emphasis is placed on progress in development of high temperature materials for coating protection against oxidation, hot corrosion and erosion, and in turbine cooling technology. Specific topics discussed include metal matrix composites, superalloys, directionally solidified eutectics, and ceramics.
Material categories as well as coatings and recent turbine cooling developments are reviewed. Current state of the art is identified, and as assessment, when appropriate, of progress, problems, and future directions is provided.
Several NASA-sponsored benefit-cost studies have shown that very substantial benefits can be obtained by increasing material capability for aircraft gas turbines. Prealloyed powder processing holds promise for providing superalloys with increased strength for turbine disk applications. The developement of advanced powder metallurgy disk alloys must be based on a design of optimum processing and heat treating procedures. Materials considered for high temperature application include oxide dispersion strengthened (ODS) alloys, directionally solidified superalloys, ceramics, directionally solidified eutectics, materials combining the high strength of a gamma prime strengthened alloy with the elevated temperature strength of an ODS, and composites. Attention is also given to the use of high pressure turbine seals, approaches for promoting environmental protection, and turbine cooling technology.
Significant progress has recently been made in many high temperature material categories pertinent to such applications by the industrial community. These include metal matrix composites, superalloys, directionally solidified eutectics, coatings, and ceramics. Each of these material categories is reviewed and the current state-of-the-art identified, including some assessment, when appropriate, of progress, problems, and future directions.
Materials for intermediate temperature applications are considered, taking into account possibilities regarding the use of prealloyed powder processing to obtain superalloys with increased strength for turbine disk applications. Materials for high temperature application are also discussed. Attention is given to oxide dispersion strengthened alloys (ODS), ceramics, directionally solidified eutectics, ODS + gamma prime alloys, and composites. A description is presented of various approaches for providing environmental protection.
Survey reviews the structural applications of refractory metals and the special problems they present in manufacture, evaluation, and application. The unique facilities required for their processing and evaluation, a summary of accomplishments in achieving commercial products, and the present status of the most advanced refractory materials are presented.
NASA derived metallic and composite materials with special properties for utilization in electric power industry
Alloying and strengthening mechanisms for heat resistant refractory metals
Applications for new class of materials termed oxide-dispersion strengthened materials offering stability at high temperatures and high thermal and electrical conductivity
High temperature, oxide-dispersion hardened alloy uses in turbojet engines, reentry vehicles, and other applications
High temperature nickel and cobalt superalloys for turbojet engines
Processing, testing and application of refractory metals to various high temperature environments
Progress in refractory metals for structural applications - facilities, manufacturing, processing, and research and development
Material development review of high temperature materials, superalloys, alloys, and refractory metals for turbojet engines
Material research and development requirements for space vehicles, covering thermal control, cryogenic uses and material systems