【摘要】 提出了一种虚拟材料法,用以消除铍激光热传导对接焊热过程数值分析中钎料与母材间的对接间隙所带来的能量边界条件.假定对接间隙被一种具有不同于母材和钎料的热物性参数的虚拟材料所填充,用指数旋转抛物线体热源模型预测了铍激光热传导对接焊缝横断面轮廓,并进行了试验研究.结果表明,在考虑对接间隙的情况下计算所得的熔池轮廓更接近于试验结果.虚拟材料的导热系数对熔池形状的影响较大,而密度和比热对熔池形状的影响较小.随着导热系数的增大,熔深和熔宽均逐渐减小.当导热系数取30 W/(m.K)时,计算所得的熔池形状与试验测得的值吻合良好.更多还原

【Abstract】 A new method was presented to deal with the numerical analysis of heat transfer in laser heat-conduction butt welding of Beryllium plate,in which the gap was assumed to be filled with a material with specific themophysical parameters that were different from those of solder and base metal.The weld pool contours on cross section were predicted by using an exponential rotary parabolic body heat model.Besides,experiments were performed to validate the method.Results show that the predicted weld pool contours are more close to that of experimental results if gap is taken into account.The thermal conductivity of the material has great effect on the weld pool shape,while the density and specific heat have less.As the thermal conductivity increases,both weld depth and weld width decrease.When the thermal conductivity takes 30 W/(m·K),the predicted weld pool contours show good agreement with the experimental measured ones.更多还原