摘要
采用填充式摩擦点焊技术对镁/铝异种金属进行工艺试验,并对点焊接头的力学性能和微观组织进行分析.结果表明,当采用合理的搭接接头设计和工艺参数进行镁/铝异种金属摩擦点焊时,可获得表面平整、抗剪切能力强的焊点,其焊点剪切力可达1 865 N.组织分析发现,在焊核与镁母材之间的竖直界面处易出现少量的孔洞、微裂纹等缺陷,接头的断裂正发生在该区;而在镁/铝之间的水平界面结合良好,存在一定厚度的界面层组织,且该界面层组织的硬度要比两侧母材的硬度明显高很多,这与摩擦点焊过程中脆硬相的金属间化合物的形成有关.
Experiments of refill friction spot welding of Mg / Al dissimilar metals were carried out. The mechanical properties and microstructure of the joints were tested and analyzed. The results showed that the weld spots had smooth appearance and high shear strength,and the shear stress could reach 1 865 kN at the proper welding parameters if the lap joints were properly designed. Little cavity and microcracks are found on the nugget / Mg vertical interface,where is the fracture zone. At the horizontal nugget / Al interface with certain thickness,where the microhardness is obviously higher than that of two-side materials, which has some relation with the formation of brittle and hard intermetallics.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2013年第11期41-44,115,共4页
Transactions of The China Welding Institution
基金
国防基础科研资助项目(A0320110014)
关键词
填充式摩擦点焊
异种金属
力学性能
微观组织
refill friction spot welding
dissimilar metals
mechanical properties
microstructure
