摘要
采用回填式搅拌摩擦点焊焊接0.6 mm厚的LY12铝合金,研究不同参数下接头的显微组织及力学性能。根据焊接接头的组织特征将其分为搅拌区、热机影响区、热影响区和母材,结果表明:焊后试件无明显变形,搅拌区形成细小的等轴晶粒组织,热机影响区形成纤维组织,部分晶粒发生回复再结晶,搅拌区的硬度值最大,热机影响区的值最小;旋转速度和焊接时间分别增加,其剪切力先增大后减小;剪切断裂形式为塑性断裂,裂纹起始于边界,沿板厚方向扩展,断口中心处韧窝组织分布均匀。最佳的焊接工艺参数为转速2 000 r/min、下压量0.2 mm、焊接时间3.5 s、下扎深度0.8 mm。
The microstructure and mechanical properties of 0.6 mm thick LY12 aluminum alloy were studied by using the refill friction stirspot welding. According to the characteristics of welded joints, it is divided into the stir zone, thermo mechanically affected zone, heataffected zone and base metal. The results showed that there was no obvious deformation of the specimen after welding, the stir zone formedfine equiaxed grain, TMAZ formation of fibrous tissue, some grains during recovery and recrystallization, the stir zone of maximumhardness, the minimum value of the thermo mechanically affected zone, the rotational speed and welding time increased respectively, andthe shear force increased first and then decreased, the shear fracture mode was brittle fracture, the crack started at the boundary andexpanded along the thickness of the plate, the distribution of dimple tissue was uniform at the center of fracture, the optimum weldingparameters for rotating speed 2 000 r/min press amount 0.2 mm the welding time of 3.5 s with the depth of 0.8 mm.
作者
刘效云
王宝华
张俊粉
张春雷
贾云海
王军
张亮
LIU Xiaoyun;WANG Baohua;ZHANG Junfen;ZHANG Chunlei;JIA Yunhai;WANG Jun;ZHANG Liang(Chengsteel Group Co.,Ltd.,HeSteel Group Co.,Ltd.,Chengde 067102,China;School of Material Science andTechnology Hebei University of Science and Technology Shijiazhuang 050001 China)
出处
《电焊机》
2018年第10期8-12,共5页
Electric Welding Machine
关键词
回填式搅拌摩擦点焊
显微组织
剪切拉伸强度
塑性断裂
refill friction stir spot welding
microstructure
shear tensile strength
plastic fracture
