Mechanical properties and microstructure of Ti-6Al-4V compacts by metal injection molding

• 作者: 何新波 曲选辉 段柏华 郭世柏
• 来源期刊: 中国有色金属学会会刊（英文版）
• 学科: 工学
• 关键词: metal injection molding Ti-6Al-4V sintering time properties microstructure
• 年，卷（期）: 2004,（6）
• 页码范围: 1055-1061
• 页数: 7页
• 分类号: TG146.2
• 语种: 英文

摘要

Ti-6Al-4V compacts were fabricated by metal injection molding(MIM). Influence of vacuum sintering time on mechanical properties and microstructure of the sintered compacts at 1 260 ℃ were investigated. The experimental results show that the compacts sintered at 1 260 ℃ for 3 -6 h, which was made from hydrogenation-dehydrogenation(HDH) powder(average particles size is 45 μm), have a relative density of 95.6%- 96.7%, ultimate tensile strength of 648 - 686MPa and 0.2% yield strength of 526 - 615MPa; but a lower elongation(＜4%) and that the compacts sintered at 1 260 ℃ for 2 - 6 h, which was made from 90% gas-atomized powder(average particles size is 32.5 μm) and 10 % HDH powder, have higher relative density(＞95 %), ultimate tensile strength of 800 -848MPa,0.2% yield strength of 712 - 762MPa and high elongation (7.4%- 9.5%). When the sintering time is increased,porosity decreases and microstructure of sintered products changes from equiaxed to typical Widmanstatten, the average sizes of prior β grains, α colonies and α phase thickness in the β grains increase accordingly. After HIP treatment,pores obviously become less, microstructure of alloy is refined and mechanical properties are greatly improved.