5A02铝合金CO_2激光焊接头组织和力学性能分析  

Microstructure and mechanical properties in laser beam welding of 5A02 Aluminium alloys

作　　者：曹丽杰[1] 

机构地区：[1]上海工程技术大学机械工程学院,上海201600

出　　处：《电焊机》2011年第7期63-67,共5页Electric Welding Machine

摘　　要：对2mm厚的5A02铝合金进行CO2激光焊接试验研究。分析激光焊缝成形和接头微观组织形态,测定了接头上表面和焊缝厚度方向上的维氏硬度,并对接头进行横向和纵向拉伸试验,用扫描电镜观察分析拉伸断口形貌。结果表明,激光功率和焊接速度合理匹配能够获得成形良好、无缺陷的焊缝,焊缝中部为等轴细晶,熔合线附近是柱状晶组织。焊缝各区域硬度高于母材,焊缝中部厚度方向上硬度基本相同,焊缝的平均屈服强度是母材的1.78倍,平均抗拉强度是母材的1.51倍。母材横向拉伸断口韧窝较深,为延性断裂;焊缝纵向拉伸断口韧窝较浅,具有延性和脆性断裂两种特征。2 mm thick aluminium alloys 5A02 plates were welded using CO2 laser beam in this paper.The laser weld formation and microstructure morphology were studied,the hardness on top and in the weld thickness were measured,also transverse and longitudinal tensile test were made.Moreover,tensile fractographys were analysed with SEM.The test result shows that the cooperation of laser power and welding speed can lead to perfect welds.There are equiaxed grains in center welds.The hardness in the fusion zone is higher than that in the base metal.The longitudinal average yield strengths of the welds were about 178% those of the base metals.The longitudinal average tensile strengths of the welds were about 151% those of the base metals,the base metal with deep dimples displayed a ductile type of fracture,and the welds with shallow dimples displayed ductile and brittle type of fracture.

关 键 词：铝合金 CO2激光焊接 组织 性能 

分 类 号：TG456.7[金属学及工艺—焊接]