一种激光热传导钎焊的热源模型

A heat source model for laser heat-conduction brazing

根据熔池具有较小深宽比的特征,发展了一种适合于铍板激光热传导钎焊的热源模型.分别建立了由表面高斯热源和内部旋转体积热源,按不同比例构成的复合热源、指数旋转抛物线体热源和线性旋转抛物线体热源三种模型.利用这三种模型计算了同一焊接条件下起焊点前2 mm处一点的焊接热循环曲线和熔池横断面轮廓,并进行了试验验证.目前的研究中用前两种热源模型计算所得的熔池横断面轮廓与试验结果相符,用线性旋转抛物线体热源的计算得不到熔化的熔池.结果表明,由于其参数少且与试验结果吻合良好,指数旋转抛物线体热源模型是最佳的热输入模型.

A heat source model suitable for laser heat-conduction brazing of Beryllium plates was developed according to the weld pool with a characteristic of small depth-width ratio.Three models were established respectively such as the compound heat source model that combined Gauss model with rotary body model in different proportions,the exponential-rotary parabolic body heat source model and the linear-rotary parabolic body heat source model.The thermal cycle curves of a point 2 mm ahead the start point and weld pool contours on cross section were predicted under same welding conditions by the three models,and welding experiments were performed to verify the models.The weld pool contours predicted by the two former models were compared in one experiment and the result showed they were.Meanwhile,it could not obtain a weld pool by using the linear-rotary parabolic body heat source model in current study.Results showed that the exponential-rotary parabolic body heat source model was the best one for its less parameter and good agreement with the experimental results.