TC4/QAl10-3-1.5扩散接头残余应力的有限元数值模拟

Finite Element Modeling of Residual Stresses in the Diffusion Bonding Joints of TC4/QAl10-3-1.5

采用有限元分析软件ANSYS对TC4与QAl10-3-1.5直接扩散连接和填加Ni中间层扩散连接接头残余应力分布进行了数值模拟。结果表明,对接头强度有害的轴向拉应力σy的最大值出现在靠近接头边缘的界面脆性相及焊缝TC4侧的狭小区域内,且拉应力σy随着向中心轴的靠近而迅速减小并逐渐转为压应力,因此该区域是接头的薄弱区;采用Ni中间层时,应力分布梯度相对缓和一些,最大残余应力出现在中间层Ni与TC4之间的金属间化合物NiTi、Ni3Ti上;而随着中间层厚度的增加,接头残余应力也相应的增大。中间层厚仅存在一个最佳值。

The numerical simulation of residual stresses in the diffusion bonding joints of TC4/QAl10-3-1.5 and TC4/Ni/QAl10-3-1.5 is carried out by ANSYS. The σy impairing the joint strength appears in the narrow region between the intermetallic compounds and the TC4 side. With closing the center axis, the tensile stresses rapidly minish and gradually transform into compress stresses. So, it becomes a weak region of the joint. But the stress distribution is comparatively relaxative when using Ni as interlayer. The maximal residual stress appears on the intermetallic compounds of NiTi and Ni3Ti between Ni interlayer and TC4, correspondingly, the joint residual stress increases with the interlayer thickness increasing.