基于热加工图的TC18钛合金热变形行为研究

Thermal Deformation Behavior of TC18 Titanium Alloy Based on Thermal Process Diagram

为了研究TC18钛合金相变点附近塑性成形过程中组织变化及金属流动规律,采用金相法测定实验用锻态β转变温度为1 161 K。在TC18钛合金β转变温度±20 k,应变速率0.01~1.00 s-1,最大应变0.7的情况下,对材料进行恒温-恒应变速率热模拟压缩实验。求解不同应变条件下变形速率敏感指数m,能量耗散率因子η及失稳判据ξ等参数。获得了实验情况下真实应力-应变曲线,绘制了TC18钛合金不同应变条件下热加工图,得到了TC18钛合金实验条件下材料的最佳变形区域。

In order to study the change of microstructure and metal flow in the plastic forming process near TC18 titanium alloy phase transition point,a metallographic method was used to determine the change temperature of the forging state in the experiment with 1 161 K.The transform temperature of TC18 titanium alloy was ±20 k,and the strain rate was0.01-1 s^-1,and the maximum strain was 0.7,and the thermo-constant strain rate thermal simulation compression experiment was carried out.The deformation rate sensitivity index m,energy dissipation factor η,and the instability criterion ξ were solved under different strain conditions.The results show that the experiment case real stress-strain curve is obtained,the TC18 titanium alloy hot working diagram is mapped,under the conditions of different strain is obtained under the condition of TC18 titanium alloy experiment the best material deformation area.