Published online by Cambridge University Press: 22 February 2011
Lightweight gamma titanium aluminide automotive valves may significantly improve engine performance and fuel economy. However, low cost mass production processes must be developed to realize these gains. Permanent mold casting processes and low cost heat treatments are being developed to enable commercial introduction of TiAl automotive valves. Microstructural development, tensile, creep, and high cycle fatigue properties of permanent mold Ti-47Al-2Nb-1.75Cr (at%) castings are compared with investment castings of similar size. A recommendation is made to use as-HIP castings for components not designed to damage tolerant criteria. This work was performed as part of a vertically integrated team effort to transfer aerospace TiAl technology to the automotive market.