(1. 上海航天精密机械研究所,上海 201600;
2. 华中科技大学 武汉光电国家实验室,武汉 430074)
摘 要: 以铝硅共晶合金Al-12Si为填充材料,采用光纤激光-冷金属过度(CMT)复合焊接技术制备铝/钢异种金属优质对接接头。通过SEM、EDS和XRD分析,结果表明:不锈钢和熔合区界面存在明显的金属间化合物(IMCs)层。从接头上部到下部,IMCs界面层逐渐增厚,并由锯齿状变成板块状。IMCs层通常表现为两层结构,分别为靠近钢基体侧的θ-Fe4(Al,Si)13层和靠近焊缝侧的τ5-Al8(Fe,Cr)2Si层组成。当激光偏移量为0.4 mm时,热输入的优化范围为80~110 J/mm。在此范围内,IMCs界面层厚度范围为3~8.5 μm,接头抗拉强度大于130 MPa,达到铝母材的80%以上。
关键字: 铝合金;不锈钢;金属间化合物;激光-电弧复合焊接;异种连接
(1. Shanghai Spaceflight Precision Machinery Institute, Shanghai 201600, China;
2. Wuhan National laboratory for Optoelectronics, Huazhong University of Science and Technology,
Wuhan 430074, China)
Abstract:Dissimilar metals of Al alloy to stainless steel was conducted by fiber laser-cold metal transfer (CMT) hybrid welding technique using Al-12Si filler wire. By the analyses of SEM, EDS and XRD, the results show that a IMCs layer is found at the interface between stainless steel and fusion zone. From top to bottom of the joint, the thickness of IMCs layer increases gradually and the shape changes from serrated to plate-like. The IMCs layer is usually composed of two layers, the θ-Fe4(Al,Si)13 layer near to stainless steel and the τ5-Al8(Fe,Cr)2Si layer near to fusion zone. When the offset is 0.4 mm, the optimal range of heat input is 80-110 J/mm. Within this range, the thickness of IMCs layer is 3-8.5 μm, and the tensile strength of the joint is greater than 130 MPa, which is more than 80% of the tensile strength of aluminum base material.
Key words: aluminum alloy; stainless steel; intermetallic compounds; laser-arc hybrid welding; dissimilar joining