Heat-treated microstructure and mechanical properties of laser solid forming Ti-6Al-4V alloy  

作　　者：ZHANG Shuangyin LIN Xin CHEN Jing HUANG Weidong 

机构地区：[1]School of Materials Science and Engineering, State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi＇ an 710072, China

出　　处：《Rare Metals》2009年第6期537-544,共8页稀有金属（英文版）

基　　金：supported by the Program for New Century Excellent Talents in Universities of China (No.NCET-06-0879);the National Natural Science Foundation of China (No.50331010);the Northwestern Polytechnical University Foundation of Fundamental Research (No.NPU-FFR-JC200808);the National Basic Research Program of China (No.2007CB613800);the Program of Introducing Talents of Discipline to Universities,China (No.08040)

摘　　要：The effects of heat treatment on the microstructure and mechanical properties of laser solid forming （LSF） Ti-6Al-4V alloy were investigated The influences of the temperature and time of solution treatment and aging treatment were analyzed. The results show that the microstructure of LSFed samples consists of Widmanstatten α laths and a little acicular in columnar prior β grains with an average grain width of 300 μm, which grow epitaxiaUy from the substrate along the deposition direction （27）. Solution treatment had an important effect on the width, aspect ratio, and volmne fraction of primary and secondary a laths, and aging treatment mainly affects the aspect ratio and volume fraction of primary α laths and the width and volume fraction of secondary a laths. Globular a phase was first observed in LSFed samples when the samples were heat treated with solution treatment （950℃, 8 h/air cooling （AC）） or with solution treatment （950℃, 1 h/AC） and aging treatment （550℃, above 8 h/AC）, respectively. The coarsening and globularization mechanisms of a phase in LSFed Ti-6Al-4V alloy during heat treatment were presented. To obtain good integrated mechanical properties for LSFed Ti-6Al-4V alloys, an optimized heat treatment regimen was suggested.The effects of heat treatment on the microstructure and mechanical properties of laser solid forming （LSF） Ti-6Al-4V alloy were investigated The influences of the temperature and time of solution treatment and aging treatment were analyzed. The results show that the microstructure of LSFed samples consists of Widmanstatten α laths and a little acicular in columnar prior β grains with an average grain width of 300 μm, which grow epitaxiaUy from the substrate along the deposition direction （27）. Solution treatment had an important effect on the width, aspect ratio, and volmne fraction of primary and secondary a laths, and aging treatment mainly affects the aspect ratio and volume fraction of primary α laths and the width and volume fraction of secondary a laths. Globular a phase was first observed in LSFed samples when the samples were heat treated with solution treatment （950℃, 8 h/air cooling （AC）） or with solution treatment （950℃, 1 h/AC） and aging treatment （550℃, above 8 h/AC）, respectively. The coarsening and globularization mechanisms of a phase in LSFed Ti-6Al-4V alloy during heat treatment were presented. To obtain good integrated mechanical properties for LSFed Ti-6Al-4V alloys, an optimized heat treatment regimen was suggested.

关 键 词：metal material Ti-6Al-4V alloy laser solid forming MICROSTRUCTURE mechanical properties heat treatment 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG146.21[一般工业技术—材料科学与工程]