注射成形Ti-6Al-4V合金的显微组织和力学性能
Mechanical properties and microstructure of a Ti-6Al-4V alloy by metal injection molding
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摘要: 采用金属注射成形方法制备Ti-6Al-4V合金坯体,然后利用溶剂脱脂和热脱脂工艺脱除坯中粘结剂,研究了合金在真空烧结和热等静压烧结条件下的显微组织和力学性能.结果表明:真空烧结Ti-6Al-4V合金具有典型的魏氏体组织,其初始的β晶粒粗大,β晶粒内为次生片状α和薄β相片,空隙较多,合金的强度和塑性较低;合金经热等静压处理后,组织明显细化且均匀,空隙很少或几乎没有,从而强度和塑性都有所提高.Abstract: Ti-6Al-4V compacts were prepared by metal injection molding and binders in the compacts were debound by solvent debinding and heat debinding. The microstructure and mechanical properties of the alloy under the conditions of vacuum sintering and hot isostatic pressing (HIP) sintering were investigated. The results showed the specimens by vacuum sintering had a typical Widmannstatten microstructure, which possessed coarser prior β-grains and secondary platelet α+β-phase, but the alloy had a more microporosity and a lower tensile strength and ductility. After HIP treatment, prior β-grains and secondary platelet α+β-phase became fine and uniform, and the alloy possessed a less microporosity and a higher tensile strength and ductility.