搅拌摩擦焊温度场检测新方法与数值热源模型

A new inspection method of thermal field and numerical model of heat source for friction stir welding

采用纯Zn、Sn、Al粉末,结合热电偶测温研究了8 mm厚7050-T7451铝合金搅拌摩擦焊接过程中被焊工件与搅拌工具温度场的演变规律。基于实验数据建立了搅拌摩擦焊接三维数值热源模型。试验结果表明:搅拌工具的最高温度出现在搅拌针上而非轴肩上,其温度高于420℃而小于660℃;在被焊接工件上垂直于焊接方向,其温度高于420℃、232℃的区域宽度距焊缝中心分别为大于9 mm和20 mm。计算的特殊点热历史曲线与实验数据基本吻合,搅拌区的最高温度约为453℃。

In this study,the temperature evolutions of the workpiece and tool during friction stir welded 8 mm 7050-T7451 aluminum alloy plates were investigated through the thermocouples and the pure zinc, aluminum and tin powders.A three-dimensional numerical model was developed based on the experimental data.The experimental results show that the maximum temperature is not present in the shoulder but in the probe, which is higher than 420 ℃.The widths of regions in the workpiece cross-section, where temperatures are higher than 232 ℃ and 420℃ ,are 6mm and 20 mm ,respectively.The calculated thermal histories in the special point are in good agreement with the experiments.Moreover, the simulation results indicate that the maximum temperature in the stir zone is approximately 453 ℃.