High-Temperature Deformation Behavior of Powder Metallurgy Ti-4Zr-6Al-0.6Si-0.5Mo Alloy

The hot deformation behavior of Ti-4Zr-6Al-0.6Si-0.5Mo high-temperature titanium alloy was investigated under temperatures of 800-1100 °C, strain rates of 0.001-1 s^-1, and a true strain of 0.5. Flow stress curves under different temperatures and strain rates were analyzed, and a constitutive equation that depicts the correlation among flow stress, deformation temperature, and strain rate was established. Processing maps were employed for determining the instability domains as well as optimal hot processing window. The results show that the optimal hot processing window for the alloy is a deformation temperature of 950-1100 °C and a strain rate of 0.001-0.01 s^-1. Flow instability occurred within two domains: 800-850 °C at strain rates of 0.1-1 s^-1 and 900-1075 °C at strain rates of 0.01-0.1 s^-1, where the alloy is prone to cracking, resulting in processing failure.