包套设计对典型粉末钛合金拉伸性能的影响

Effects of can design on tensile properties of typical powder metallurgy titanium alloys

采用热等静压工艺制备Ti-6Al-4V和Ti-60两种预合金粉末钛合金,研究两种不同包套形式对粉末合金拉伸性能的影响,采用SEM观察粉末合金的拉伸断口形貌,并利用MSC.Marc有限元分析软件对两种包套在热等静压过程中包套各部位的尺寸收缩进行模拟预测。结果表明:包套结构设计不合理时,焊缝在热等静压过程中存在泄漏的风险,进而会严重恶化粉末合金的性能;有限元模拟仿真可以辅助包套设计,提高效率,对制备粉末冶金近净成型构件有较为重要的工程应用意义。

Pre-alloyed powders of Ti-6Al-4V and Ti-60 were prepared through hot isostatic pressing (HIP) route. The tensile properties of two typical powder metallurgy (PM) titanium alloys HIPped from two different kinds of cans were tested, and the fracture surface morphology was studied by SEM. The simulation, using MSC.Marc software of capsule/powder shrinkage during HIPping for two different can designs was presented. The numerical simulations of Hipping experiments indicate that improper can design shows great probability of capsule failures, which is in accordance with the experimental data. Capsule failure will deteriorate the mechanical properties of the PM alloys, and finite element method is a useful tool for can design, especially for manufacturing near-net-shape components.