工艺过程对散热器电子束钎焊残余应力影响的数值模拟

利用ANSYS软件,建立二维有限元模型,分析了两种不同钎焊工艺对1Cr18Ni9Ti不锈钢散热器电子束钎焊接头残余应力的影响,旨在筛选出一种合适的工艺及参数.结果表明,对于径向残余应力,采用直接加热钎焊工艺,钎焊面上出现明显的应力集中区域;而采用分阶段加热钎焊工艺,钎焊面上没有应力集中区出现,且应力变化曲线比直接加热钎焊工艺平缓得多;对于周向残余应力,分阶段加热与直接加热钎焊工艺相比,拉应力峰值减小了11.2%.两种钎焊工艺的周向残余拉应力峰值均大于径向残余拉应力,钎焊面的危险部位沿圆周方向,即电子束扫描加热的方向.

Numerical simulation of influence of process on stress field of electron beam brazing radiator

The measurement of residual stress of electron beam brazing (EBB)is difficult, so a two-dimonsional FEM model was established to simulate the residual stress field by ANSYS softwane.And the influences of two kinds of process on residual stress of 1Cr18Ni9Ti stainless steel radiator joint of EBB were analyzed to optimize the process and parameters.The results show that, for radial residual stress, the obvious stress concentration region was found in faying face by direct-heating process;while there was no stress concentration in faying face by stage-by-stage heating process;For circumferential residual stress, conpared the stage-by-stage heating process with direct-heating process, the peak value of tensile stress reduces by 11.2%.Compared circumferential residual stress with radial residual stress by two kinds of brazing process, the peak value of circumferential tensile stress is higher than that of radial tensile stress.So the dangerous position of faying face is along circle direction, namely, the heating direction of scanning electron beam.