MATERIALS REVIEW FOR IMPROVED AUTOMOTIVE GAS-TURBINE ENGINE. FINAL REPORT

Advanced materials are the key to achieving the performance and fuel economy goals of improved automotive gas turbine engines. The potential role of superalloys, refractory alloys, and ceramics in the hottest sections of future engines that may be required to operate with turbine inlet temperatures as high as 1370 exp 0 C (2500 exp 0 F) is examined. These high temperature materials are reviewed. The characteristics of the best modern conventional superalloys, directionally solidified eutectics, oxide dispersion strengthened alloys, and tungsten fiber reinforced superalloys are reviewed; and the most promising alloys in each system are compared on the basis of maximum turbine blade temperature capability. The requirements for improved high temperature protective coatings and special fabrication techniques for these advanced alloys are discussed. Chromium, columbium, molybdenum, tantalum, and tungsten alloys are reviewed. On the basis of properties, cost, availability, and strategic importance, molybdenum alloys are found to be the most suitable refractory material for turbine wheels for mass produced engines. Ceramic material candidates are reviewed and ranked according to their probability of success in particular applications. Various forms of, and fabrication processes for both silicon nitride and silicon carbide, along with SiAlON's are investigated for use in high-stress and medium-stress high temperature environments. Low-stress glass-ceramic regenerator materials are also investigated. Treatment is given to processing requirements, such as coatings for oxidation/corrosion protection, joining methods, and machining technology. Economics of ceramic raw materials, and of various processing methods are discussed. Conclusions are drawn, and recommendations for areas of further research are proposed for consideration and/or adoption. (ERA citation 06:018915)

  • Corporate Authors:

    Chrysler Corporation

    ,    

    Department of Energy

    1000 Independence Avenue, SW
    Washington, DC  United States  20585
  • Authors:
    • Belleau, C
    • Ehlers, W L
    • Hagen, F A
  • Publication Date: 1978-4

Media Info

  • Pagination: 94 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00343401
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: NASA-CR-159673, COO-2749-47
  • Contract Numbers: AC02-76CS52749
  • Files: TRIS
  • Created Date: Oct 28 1982 12:00AM