采用Ag-Cu-Ti活性钎料连接Al₂O₃陶瓷与1Cr18Ni9Ti不锈钢, 研究了Cu, Ni和表面镀Ni的Cu 3种中间层金属对钎焊接头组织和剪切强度的影响. 结果表明, Cu作为中间层时, 陶瓷与钎料能形成良好的界面反应; Ni作为中间层时, 焊缝中形成大量的Ni₃Ti金属间化合物, 导致陶瓷/钎料不能形成良好的反应层, 降低了接头的剪切强度; 表面镀Ni的Cu片作为中间层金属时, 少量Ni的存在不影响钎料中活性元素Ti的含量, 钎料与陶瓷能形成良好的界面反应, 同时Ni层的存在降低了钎料对Cu的溶蚀作用, 该种中间层更能有效地缓解钎焊接头的残余应力. 当Ni层的厚度为30 mm, Cu片的厚度为0.2 mm时, 接头剪切强度可达到109 MPa。

In recent years, there have been great efforts focused on joining ceramics to metals to establish processes for a wide range of industrial uses. Several important problems, however, still remain unsolved. Among them, how to produce atomic bonds at ceramic/metal interfaces and how to minimize the residual stress due to large thermal expansion mismatch between two constituents are the most critical. The thermal expansion mismatch effect is a serious problem because, even if a strong interface could be achieved, joints with large residual stress are easily broken. Therefore, it is desirable to reduce the magnitude of the residual stress. Some researchers have succeeded in achieving a strong joint between alumina and stainless steel by using a soft metallic interlayer. In this study, the effects of interlayers of nickel, copper and copper coated with nickel on the microstructure and shear strength of alumina ceramic and 1Cr18Ni9Ti stainless steel bonding with Ag-Cu-Ti filler metal were investigated. The results indicated that, when using copper as an interlayer, sufficient interfacial reaction between the ceramic and the filler metal could obtain. However, when using nickel as an interlayer, resulting in an insufficient reaction between the ceramic and the filler metal and the formation of large amount Ni₃Ti intermetallic compounds, and thus, the strength of the joint decreased heavily. It is very interesting that when using copper coated with Ni, the existence of the small amount of nickel didn't affect the activity of titanium in the filler metal, meanwhile, it decreased the effect of the filler metal on the solubility of copper. Compared with copper and Ni interlayer, this interlayer could reduce interfacial residual stress more effectively. And the shear strength of 109 MPa was obtained when the thickness of Cu was 0.2 mm coated with 30 μm thick nickel。