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采用包套热等静压工艺制备了洁净Ti55粉末合金。根据Ti55预合金粉末的β转变温度选择了两个热等静压成型温度,分析了Ti55粉末合金对热等静压温度和后续的热处理制度的响应。结果表明:在940℃和970℃热等静压成型的粉末合金,其显微组织和拉伸性能的差别不大。考虑到在构件热等静压成型过程中存在温度/压力场分布不均匀引起的致密化波动效应,本文优选的热等静压温度为940℃。固溶时效热处理使粉末合金600℃的拉伸性能显著提高,其拉伸性能优于铸造合金,接近锻造合金的水平。有限元模拟仿真可辅助包套/模具设计,提高效率,是粉末冶金近净成型构件制备的有效计算仿真工具。应用有限元仿真辅助包套模具设计,采用热等静压工艺成型了Ti55粉末冶金薄壁筒体结构。
The hot isostatic pressing process was adopted to prepare the clean Ti55 powder alloy. Two hot isostatic pressing temperatures were selected according to the β transformation temperature of Ti55 prealloyed powders. The response of Ti55 powder alloy to hot isostatic pressing temperature and subsequent heat treatment was analyzed. The results show that there is no significant difference in microstructure and tensile properties between hot isostatic compaction powder alloys at 940 ℃ and 970 ℃. Considering the dewetting fluctuation caused by the uneven temperature / pressure field during the hot isostatic compaction of the component, the preferred hot isostatic pressing temperature is 940 ℃. The heat treatment at solution treatment significantly improves the tensile properties of the powder alloy at 600 ℃, and its tensile properties are better than that of the cast alloy and close to that of the forged alloy. Finite element simulation can assist the envelope / mold design and improve efficiency, which is an effective calculation and simulation tool for the preparation of near net shape components of powder metallurgy. Finite element simulation is used to assist the design of cladding mold. The structure of Ti55 powder metallurgy thin-walled cylinder is formed by hot isostatic pressing process.