Ti-10V-2Fe-3Al合金热变形的研究

Investigation on Hot Deformation Behavior of Ti-10V-2Fe-3Al Alloy

利用Gleeble3500热模拟试验机对Ti-10V-2Fe-3Al合金两种状态在不同变形温度及不同变形速率条件下的热变形行为进行了研究。结果表明,不同初始状态对合金的应力应变行为影响较大,经过固溶处理后在低于相变点变形时合金的流变应力比较高,但在高于相变点变形时流变应力没有明显差异;合金的应力指数与合金的状态和应变速率有关,大概以0.1s-1为界分为低应变速率和高应变速率两部分;合金的表观激活能与材料的状态、变形温度及变形速率有关。当两种状态下的合金在温度为650～800℃、应变速率为0.001～0.1s-1范围内变形时,β相内只发生动态回复,而α相除了发生动态回复外还可能发生动态再结晶;合金在相变点以上变形时只存在着单一的动态回复机制。

The hot deformation behavior of two different microstructures of Ti-10V-2Fe-3Al alloy at temperature in the range of 650～900℃ and with strain rates from 0.001s^(-1) to 10s^(-1) had been studied using Gleeble-3500 thermal simulation testing machine. The results show that the initial microstructure greatly affects hot deformation behavior of this alloy;solution treated alloy has higher flow stress than untreated alloy under the same condition when deformation temperature is below β transus point;but flow stress has no obvious difference when deformation temperature is above β transus point;stress exponent(n) has relationship with microstructure and strain rate;stress exponent is approximately divided into two regimes by strain rate 0.1s^(-1). Whereas the apparent activation energy(Q) is affected by microstructure, temperature and strain rate. Within the β phase dynamic recovery takes place but within the α phase dynamic recrystallization may take place besides dynamic recovery when the alloy is deformed at temperature in the range of 650～800℃ and with strain rates from 0.001s^(-1) to 0.1 s^(-1). However, the only restoration mechanism is dynamic recovery when the alloy is deformed above β transus point.