Ti14合金触变可锻性研究

Thixoformability of Ti14 Alloy in Semi-Solid State

通过模拟镦锻压缩和模锻实验研究Ti14合金半固态下的触变锻造特性,分析了锻造过程中的组织演变过程,测定了锻件的力学性能,并综合讨论了该合金半固态下的触变可锻性.结果表明：Ti14合金在半固态较常规固相下具有较小的镦锻变形抗力;其中,1000到1100℃之间触变镦锻变形量可达70％～85％.半固态模锻结果表明：1000和1050℃下,合金在变形量为45％～75％时表现出良好的可锻性,锻件表面无明显缺陷.分析认为：由于液相的协调变形机制,半固态下触变模锻较常规模锻,减少了晶界处的应力集中,有效降低了合金的变形抗力;同时,触变锻造可以有效细化晶粒,提高力学性能,改善合金的成形性.

The thixoformability of Til4 was evaluated by upsetting and die forging tests,and the microstructure and mechanical properties of the forgings were also investigated.The results show that low upsetting force and excellent upsettability with the upsetting reduction in height of 70％～85％ could be obtained in semi-solid state ranging from 1000 to 1100 ℃.Die forging tests also show the excellent workability with a forging ratio of 75％ in the temperature range of 1000 to 1050 ℃.It is found that the existence of liquid on grain boundary may serve to relax the stress concentrations caused by solid deformation,causes low deformation resistance and finally improves forgeability of the alloy.The microstructure of samples reveals that dynamic recrystallization might occur during thixoforging and the grain refinement is attained,which also benefit in the improvement of the semi-solid formability and mechanical properties of forgings.