摘要
采用交流电阻点焊焊接了AZ31B镁合金,研究了点焊接头力学性能的变化规律,分析了点焊接头的显微组织。结果表明:接头抗剪强度随焊接规范呈规律性变化,存在最佳值;表面状态对接头拉剪强度影响很大;接头熔核区显微组织为单一的等轴晶,在α-Mg固溶体的晶界网络处析出β-Mg_(17)Al_(12)离异共晶体;焊点中的裂纹为沿晶热裂纹,断口显现出韧窝沿晶界撕裂的特点。
AZ31B magnesinm alloy is welded by AC spot
welder, mechanical properties and microstructure of the joints
are studied. The results showed that tensile shear load of joints
change regularly with increasing of welding variables and the
optimum is up to 2097 N. The surface conditions have signifi-
can influence on the properties of joints. There are single fine
equiaxle crystals in the nugget, of which the structure is
β-Mg_(17)Al_(12) precipitated on α-Mg boundaries induced by
non-equibrium freezing, and hot cracks in the joints. Fracture
analysis results show the characteristic that dimples tear along
intercrystallines.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2004年第5期131-135,共5页
Journal of Mechanical Engineering
基金
国家863计划资助项目(2002AA331160)
