Status and prognosis for alternative engine materials

The current state of research and development of new materials for advanced aircraft engines is reviewed. The advantages and disadvantages of intermetallic compounds and refractory metals as replacements for today's nickel-base alloys are discussed along with some results of research directed at overcoming some of the problems which restrict their application. It is concluded that continuous fiber reinforced intermetallic matrix composites offer one of the best chances for success. However, major technical barriers still exist, especially in the development of suitable fibers. The introduction of these materials into aircraft engines is expected to take in excess of 5 to 10 years.