Enhancing the High Temperature Capability of Ti-Alloys (original) (raw)

Titanium is a widely used structural material for applications below approximately 5008C but right now it cannot be used at higher temperatures. Titanium forms a fast growing rutile layer under these conditions. Furthermore enhanced oxygen uptake into the metal subsurface zone leads to embrittlement which deteriorates the mechanical properties. To overcome this problem a combined Al-plus F-treatment was developed. The combination of Al-enrichment in the surface zone so that intermetallic Ti x Al y-layers are produced which form a protective alumina layer during high temperature exposure plus stabilization of the Al 2 O 3-scale by the fluorine effect led to significantly improved resistance against increased oxidation and embrittlement in high temperature exposure tests of several Ti-alloys. In this paper, the experimental procedures and achieved improvements are described. The results will be discussed for the use of Ti-alloys at elevated temperatures.