2195铝锂合金搅拌摩擦焊工艺

试验研究了8 mm厚2195-T8铝锂合金板材搅拌摩擦焊工艺，分析了不同搅拌针结构设计对焊缝内部质量的影响，研究了工艺参数对接头表面成形的影响，测试了接头的力学性能。结果表明，使用圆锥螺纹+三个斜面结构的搅拌针焊接，接头内部质量更好；在室温和低温(-196 ℃)条件下，接头抗拉强度和断后伸长率都呈现出随焊接速度的增加先增加后减少的趋势，当焊接速度为100 mm/min时，室温和低温(-196 ℃)下接头抗拉强度、断后伸长率都达到最高值，接头抗拉强度分别为428 MPa，538 MPa，断后伸长率分别为4.9%，7.4%；接头断裂位置位于热影响区，断口呈45°剪切断裂，断裂部位有明显颈缩。

Friction stir welding process of 2195 Al-Li alloy

2195 Al-Li alloy plates with 8 mm in thickness were welded by friction stir welding, the influence of the stir pin shape on the welding quality of the joint was analyzed, the effects of welding parameters on the surface appearance of the joint were analyzed and the mechanical properties of the joint were tested. The results show that well performance of the joint could be obtained when the stirring head was the shape of the taper screw thread with three cants. At the temperature of -196 ℃ and the room temperature, with the increase of the welding speed, both the tensile strength and the elongation rate firstly increase to a maximum value and then decrease. At the welding speed of 100 mm/min, the tensile strength and the elongation reach the maximum value at the both low temperature(-196 ℃) and room temperature, the tensile strength of the joint are 428 MPa and 538 MPa , and the elongation rate are 4.9% and 7.4%. The fracture location of the joint is located in the heat affected zone, the fracture produced on the plane at an angle of 45° to the tensile loading direction, and the fracture surfaces showed a ductile failure with visible neck along the thickness direction.