5B70铝镁钪合金搅拌摩擦焊接头组织与性能  

Microstructures and mechanical properties of Al-Mg-Sc alloy 5B70 welded joint by friction stir welding

作　　者：苏志强[1] 张玉芝[1] 田志杰[1] 王铁鑫 陈文千 

机构地区：[1]首都航天机械公司,北京100076

出　　处：《焊接技术》2017年第11期32-35,共4页Welding Technology

摘　　要：采用搅拌摩擦焊工艺对6 mm厚5B70铝镁钪合金板材进行了焊接试验,对焊接接头的组织和力学性能进行了研究。研究结果表明:接头的抗拉强度可达385.2 MPa,强度系数为0.93,断后伸长率为11.5%;接头属于韧性断裂,接头上部韧窝尺寸大于中、下两部分的韧窝;接头硬度分布曲线呈W形,硬度最低处出现在前进侧热机影响区和热影响区;接头下部的硬度明显高于上部;BM区分布大量的Al_3Sc相,搅拌摩擦焊接头各区域经过焊接作用后仍然分布Al_3Sc相,而在HAZ区出现了Al_(12)Mg_(17)相。Al-Mg-Sc alloy 5B70 plates with the thickness of 6 mm was welded by friction stir welding and the microstructures and mechanical properties of the joint were investigated. Results indicated that the joint with excellent mechanical properties could be obtained. The tensile could reach up to 385.2 MPa which was the 93% of that of the parent metal and the maximum elongation at fracture was 11.5%. The fracture of the joint was the mode of ductile fracture. The joint hardness distribution curves showed W shape. The serious softening poing was at the TMAZ and HAZ of advance side. The upper part of joint hardness was weaker than the lower part. Large amounts of Al_3Sc particles distributed at the BM and the joint of friction stir welding. The Mg_(12)Al_(17) particles distributed at the HAZ.

关 键 词：铝镁钪合金 搅拌摩擦焊 焊缝组织 力学性能 

分 类 号：TG453.9[金属学及工艺—焊接]