铝/铝基SiC锁底接头微搅拌摩擦焊工艺特性

Investigation on micro fricition stir welded lock joint of thin Al-alloy/SiC reinforced Al composite

对薄壁铝合金/铝基SiC复合材料锁底接头微搅拌摩擦焊接工艺特性、接头形貌特征及力学性能进行研究.结果表明,当铝合金位于前近侧,搅拌针无偏移且压入深度合适时,在较宽的工艺参数窗口内均可得到成形良好的焊缝.由于微搅拌摩擦焊所特有的金属流动特点以及SiC颗粒难以流动的特性,搭接界面呈现出形状复杂的特殊形貌.不同工艺参数下得到的接头断裂路径不同,决定着接头强度的差异,强度高低取决于断裂路径是否穿过铝合金及铝基SiC材料内部.

The micro friction stir welding of lock joint of thin Al-alloy plate with a thickness of 0. 8 mm and SiC reinforced Al composite were investigated,concentrating on the process characteristics,macro-morphology of weld cross-section and mechanical properties of the joints. The results show that when the Al-alloy plate is on the advancing side and with suitable indentation depth,welds of good appearance can be obtained in a wide range of process window. The weld cross-section shows special interface morphology,caused by the characteristics of micro friction stir welding process and SiC particles. The joints under different welding parameters show different crack paths,leading to different mechanical properties. And the joint mechanical properties depend on whether the failure path propagates through the Al-alloy and SiC reinforced Al composite base metal.