Ti-47.at% Al合金的等温锻造模拟

Simulation of isothermal forging of Ti-47.at% Al alloy

采用热摸投压缩试验研究了粉末冶金Ti-47.at％Al合金在温度为900-1200℃、泣变速率为0．001-0．02s^-1范固内昀高温变形特性，发现合金的流动应力应变曲线具有流变软化特性，并得出该合金绚流变应力本构模型．利用有限元软件对Ti-47.at％Al合金V型件在不同工艺参数下昀等温锻造过程进行摸掇。结果表明，提高变形温度和碱小锻造速度，都毹降低锻造所需昀戴荷，且使温度和等效应交分布也越均匀，不另产生裂纹，而且预成型坯的形状对锻造过程也有很大影响．

The hot deformation characteristics of PM Ti - 47. at% Al alloy were studied in the tern- perature range of 900-1200℃ and strain rate range of 0.001 - 0. 02s- 1 by hot compression test. The stress -strain curves exhibited an obvious flow softening character and the flow stress model was established. The obtained flow stress model was embedded in FE model to simulate the isothermal forging process of Ti -47. at% Al V- shape part under different processing conditions. The simulation results show that the isothermal forging can decrease the load, make the temperature and effective stress distribution more uniform, and avoid the crack generating by increasing the deformation temperature or decreasing the die speed.