论文部分内容阅读
采用搅拌摩擦焊方法对18 mm厚LF21铝合金进行对接焊,利用光学显微镜、精密拉伸仪等分析测试手段,研究了焊接工艺参数对焊缝成形及焊接接头分层力学性能的影响。结果表明,在所选工艺参数范围内,焊缝表面成形良好,无裂纹、孔洞,接头抗拉强度基本保持不变;接头分层抗拉强度比整体抗拉强度小约10 MPa。当旋转速度为195及235 r/min时,层与层之间的强度变化不大;而当旋转速度为300 r/min时,层与层之间的强度出现较大波动,接头底部以及轴肩以下5 mm位置处的强度下降。适当降低搅拌头的旋转速度有利于塑性金属的充分流动。
The friction stir welding method was used to make the butt welding of 18 mm thick LF21 aluminum alloy. The microstructure and mechanical properties of the LF21 aluminum alloy were studied by using optical microscope and precision tensile tester. The results show that the weld surface is well formed and free of cracks, and the tensile strength of holes and joints remains basically unchanged within the range of the selected process parameters. The tensile strength of the joint delamination is about 10 MPa less than the overall tensile strength. When the rotation speed is 195 r / min and 235 r / min, the strength between layers does not change much. When the rotation speed is 300 r / min, the strength between the layers fluctuates greatly. The strength at 5 mm below the shoulder drops. Appropriate to reduce the rotation speed of the mixing head is conducive to the full flow of plastic metal.