两种热等静压工艺对Ti6Al4V合金力学性能影响的研究  

Mechanical Properties of Ti6Al4V Alloy Prepared by Two Different Hot Isostatic Pressing Processes

作　　者：黄俊[1] 薛鹏举[1] 蔡超[1] 魏青松[1] 史玉升[1] 刘锦辉[2] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074 [2]黑龙江科技大学现代制造工程中心,黑龙江哈尔滨150022

出　　处：《稀有金属》2016年第2期97-103,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51375188);黑龙江省自然科学基金重点项目(ZD201104)资助

摘　　要：以等离子旋转电极法制备60～200μm粒径的Ti6Al4V合金粉末为材料,研究了两种热等静压工艺（HIP）对Ti6Al4V合金室温拉伸性能与疲劳性能的影响。结果表明：在同时升温升压和先升温后升压HIP工艺下,Ti6Al4V合金的室温拉伸性能相当,抗拉强度σb分别为970和980 MPa,屈服强度σ0.2分别为876和880 MPa,断后延伸率δ分别为9.1%和10.0%;与同时升温升压HIP工艺相比,先升温后升压HIP工艺可明显改善合金的疲劳性能,疲劳极限分别为350和450 MPa。微观组织分析得出：同时升温升压粉末致密化过程中,粉末颗粒的靠近和重排先于颗粒的塑性变形,原始颗粒边界呈较规则空间多边形结构,没有大的变形和破碎,并且颗粒表面杂质元素扩散不充分;先升温后升压粉末致密化过程中,粉末颗粒靠近和重排与颗粒的塑性变形同时发生,原始颗粒边界发生大的塑性变形而被破碎,颗粒之间存在相互插入与包裹,颗粒表面杂质和偏析元素扩散充分,因而先升温后升压HIP工艺后微观组织较粗大,但有更好的疲劳性能。Taking Ti6Al4 V alloy powder with size of 60 ～ 200 μm prepared by plasma rotating electrode process as experimental material,the effects of the two different hot isostatic pressing（ HIP） processes on the room temperature tensile properties and fatigue properties of HIP specimens were tested. The result showed that under the process of in-phase increasing temperature and pressure and the process of firstly increasing temperature and secondly increasing pressure,the specimens had similar room temperature tensile properties. The corresponding tensile strengths σbwere 970 and 980 MPa,respectively. And the yield strengths σ0. 2were 876 and 880 MPa,respectively. The elongations δ were respectively 9. 1% and 10. 0%. The specimens fabricated under process of firstly increasing temperature and secondly increasing pressure had better fatigue performance with the fatigue limit stress of 450 MPa compared with those under process of in-phase increasing temperature and pressure with the fatigue limit stress of 350 MPa. The microstructure result showed that during the densification of process of in-phase increasing temperature and pressure,the stage of adjoining and rearrangement of the particles were prior to the stage of local plastic deformation on the boundary. The prior particle boundaries existed as regular spatial polygonal structure without big deformation and being broken. And particle surface diffusion of impurity element was insufficient. During the densification underprocess of firstly increasing temperature and secondly increasing pressure,the stage of adjoining and rearrangement of the particles happened at the same time with the stage of large plastic deformation. Powder particles were compressed and even torn,and as a result prior particle boundaries were broken into pieces. Powder particles wrapped and inserted to each other. What＇s more,the impurity on the particle surface reduced greatly using this process. Despite of coarse grain after HIP,all above had a positive impact on promoting the fatigue

关 键 词：热等静压 Ti6Al4V粉末 原始颗粒边界 致密化过程 力学性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程]