Ti6Al4V激光焊接接头非均匀梯度特征研究现状

Ti6Al4V钛合金在激光焊接过程中,由于热源密度高,在焊缝及其附近的狭窄区域形成了极大的温度梯度,并导致焊接接头形成大梯度的组织性能和残余应力。基于国内外的文献,综合研究了钛合金激光焊温度、接头组织、显微性能与残余应力的非均匀梯度特征。研究表明,对于焊接接头大梯度特征的研究,主要集中在分析组织、性能和残余应力的不均匀性方面,而未对梯度特征做出定量分析与评价。因此,如何对焊后组织性能和残余应力的梯度特征进行有效直观的量化表征,对于激光焊接接头的整体性能及安全评价有着重要的意义。

Research Status of Heterogeneous Gradient Feature for Laser Welded Joint of Ti6Al4V Alloy

During the process of laser welding for Ti6Al4V alloy, there is large temperature gradient in the weld and the narrow area nearby because of high heat source density, which causes a large gradient of microstructure, properties and residual stress across welded joint. Based on the domestic and foreign literatures, this paper synthetically researches the heterogeneous gradient features of temperature, microstructure, mechanical properties and residual stress of titanium alloy with laser welding. The results show that the studies for large gradient features of welded joint mainly focus on the heterogeneity analysis but not on quantitative analysis and evaluation. Therefore, the method of making a quantitative characterization efficiently and intuitively for the gradient of microstructure, properties and residual stress after welding is very significant for evaluation of overall performance and safety of laser welded joints.