材料期刊网

The evolution of microstructure on aging of an (alpha+beta) titanium alloy (Ti-5Al-5Mo-5V-1Cr-1Fe) in the beta and (alpha+beta) solution-treated and quenched conditions was investigated. The presence of very fine omega phase was detected by electron diffraction for samples aged below 400 degrees C. The fine alpha aggregates are uniformly formed within beta grains by nucleating at the. particles or beta/omega interfaces. At higher temperature, the formation of omega phase is avoided and the alpha lamellae are precipitated at the preferred site of grain boundary and then within the matrix. The highest hardness values are found when the alloys are aged at 450 degrees C for beta condition and 350 degrees C for (alpha+beta) condition.