汽车用不锈钢/Cu-镁合金连接接头结构和性能研究

Study on Microstructure and Properties of Stainless/Cu-Mg Joints

采用表面喷丸处理和两次连接方法获得不锈钢/Cu-镁合金连接接头。采用万能试验机测试焊接接头的拉伸强度,采用扫描电镜及自带能谱仪观察连接接头显微组织及元素分布,采用显微硬度计检测材料显微硬度。结果表明,不锈钢表面喷丸处理可以细化表面晶粒。不锈钢表面处理后在连接温度900℃、保温时间20 min、连接压力20 MPa下成功实现不锈钢/Cu连接。不锈钢/Cu-镁合金连接接头拉伸强度随连接温度和保温时间增加呈先增加后减小的趋势,最大拉伸强度达34.4 MPa。

The surface peening treatment and two connection methods were used for the stainless steel/Cu - magnesium alloy joint. The tensile strength of the welded joint was tested by universal testing machine. The microstructure of the bonded joint was studied by SEM and the element distribution is tested by bringing energy spectrometer. The microhardness profile of the welded joint was characterized by using microhardness tester. The results show that the stainless steel surface peening treatment can refine the grain surface. Stainless steel surface treatment after connection is at 900 ？C, holding time for 20 min, the pressure of 20 MPa successful implementation of stainless steel/Cu connections. The tensile strength of stainless steel/Cu- magnesium alloy joint increases with temperature and holding time increasing, which shows a trend of decrease after first increase, the maximum tensile strength of the welded joint is 34.4 MPa.