铝合金表面电弧喷涂Ag基涂层及其低温钎焊行为

在波导器件中，铝合金壳体较差的润湿性制约了其与微带电路板之间大面积、可靠低温钎焊连接. 通过电弧喷涂技术在5A06铝合金表面制备了厚度约为80 μm的Ag-15%Ni(质量分数)单一涂层和Ni-5%Al/Ag-15%Ni(质量分数)复合涂层，以提升Sn-Pb钎料在其表面的润湿性. 对比研究了两种涂层的显微结构、涂层界面结合性能、低温钎焊行为及钎焊接头剪切失效机制. 结果表明，涂层与铝合金基板间形成了良好的界面结合，并且两种涂层均具有较好的低温焊接性. 其中，Ag-15%Ni单一涂层与铝合金基板的结合强度为40 MPa，喷涂后铝合金基板与T2紫铜形成的钎焊接头抗剪强度为26 MPa. 相较而言，Ni-5%Al /Ag-15%Ni复合涂层展现出更佳的涂层结合强度(42 MPa)和钎焊接头抗剪强度(31 MPa).

Arc spraying Ag-based coating on aluminum alloy surface and its low-temperature soldering behavior

In waveguide devices, large-area and reliable low-temperature soldering bonding between the aluminum alloy shell and the microstrip circuit board were difficult because of the poor wettability of the Al alloy. In this study, Ag-15%Ni coating layer and Ni-5%Al/Ag-15%Ni composite coating layers with a thickness approximately of 80 μm were prepared on the surface of 5A06 Al alloy by arc spraying technology to improve the wettability of Sn-Pb alloy solder on the Al alloy surface. Comparable studies were performed on the microstructure, interfacial bonding behavior, low-temperature soldering behavior of the two kinds of coating layers, and the shearing failure mechanism of joints were investigated. Results showed that sound interfacial bonding was realized between the coating layer and the Al alloy substrate. Moreover, the two kinds of coating layers both exhibited good solderability at low-temperature. The bonding strength between the Ag-15%Ni coating layer and the Al alloy substrate was 40 MPa, and the shear strength of the soldering joint formed by the sprayed aluminum alloy substrate and T2 copper was 26 MPa. While, the Ni-5%Al/Ag-15%Ni composite coatings exhibited better bonding strength with the Al alloy substrate (42 MPa) and higher shear strength of the soldering joint (31 MPa) than the Ag-15%Ni single coating layer.