Effect of temperature on grain growth kinetics of high strength Ti–2Al–9.2Mo–2Fe alloy

• Grain growth kinetics over a wide range of temperatures from 820 °C to 1000 °C have been investigated.
• The solution-treated alloy at lower temperatures exhibited a good uniformity of the grain size.
• The abnormal grain growth at higher temperatures.
• The lower grain growth exponent values (n) and the higher activation energy (Q) of Ti–2Al–9.2Mo–2Fe alloy.

Grain growth behaviors of a beta titanium alloy (Ti–2Al–9.2Mo–2Fe) have been systematically investigated for various temperatures. Quantitative evaluations of the grain growth kinetics over a wide range of temperatures from 820 °C to 1000 °C have been performed. The results showed that the isothermal grain growth kinetics followed the normal growth behavior. The solution-treated alloy at lower temperatures (820–900 °C) exhibited a good uniformity of the grain size. It showed a poor uniformity of the grain size due to the abnormal grain growth at higher temperatures (950–1000 °C). The grain growth exponent values (n) were at the range of 0.1–0.2, about 0.1 at lower temperatures and about 0.2 at higher temperatures. They were lower than other beta titanium alloys. The lower exponent values (n) and the higher activation energy (Q) can be attributed to the solute drag effect and the high Mo content with low diffusivity in Ti matrix.