Microstructure evolution and fracture behaviour for electron beam welding of Ti�??6Al�??4V

Bulletin of materials science

Feng Jicai¹  Wu Huiqiang¹  He Jingshan¹ 

[1] State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, P.R. China$$State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, P.R. ChinaState Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, P.R. China$$

关键词: Electron beam welding;    microstructure evolution;    fracture behaviour;    titanium alloy.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The effect of microstructural characteristics on fracture behaviour mechanism for electron beam welding of Ti�??6Al�??4V was investigated. The results indicated that the welded microstructure composed of coarse needle �? + �? phases presenting disordered and multidirectional short needle morphology to make fracture mechanism complex. The coarse grains in weld seam with microhardness 536 HV were easy to be fractured in the region where welding heat input was �? 68.8 kJ/m. There exists flat curves of Ti, Al and V, Fe concentration distribution fluctuation to cause microstructural amplitude-modulated decomposition to increase the joint ductility and cleavage strength. The uneven distribution of the partial micropores located at the interior of the specimen acting as crack initiation sites lead to non-linear branch propagating path. The �? + �? interlaced structure results in the fracture location near �?/�? interface. The existence of stacking fault structure caused pile-up of dislocation to produce micropores to be new fracture initiation sites.

【 授权许可】

Unknown