用非晶态合金作中间层扩散连接Si_3N_4与40Cr钢的研究

DIFFUSION BONDING OF Si_3N_4 AND 40Cr STEEL WITH AMORPHOUS Cu_(50)Ti_(50)B INTERLAYER

本文采用非晶态Ｃｕ_（５０）Ｔｉ_（５０）Ｂ薄膜和纯Ｎｉ缓释层作复合中间层，较好地实现了ｓｉ_３Ｎ_４与４０Ｃｒ钢的扩散连接，连接时间和连接温度及缓释层厚度对接头的强度影响很大最佳连接工艺为：９００℃·４０ｍｉｎ·３０ＭＰａ，Ｎｉ缓释层的合适厚度为１ｍｍ接头的微观分析表明：缓释层与非晶态Ｃｕ_（５０）Ｔｉ_（５０）Ｂ之间存在着较强的物理冶金交互作用，导致非晶态中间层中的Ｔｉ的活度降低，并产生脆性金属间化合物，使接头强度下限Ｍｏ是较理想的阻挡层材料在非晶态Ｃｕ_（５０）Ｔｉ_（５０）Ｂ与Ｎｉ缓释层之间插入Ｍｏ层，能有效地抑制两者间的物理冶金交互作用，并缓解了接头的残余热应力，提高了接头的强度本文提出了陶瓷与金属扩散连接接头的新模式为：陶瓷／用于扩散反应的中间层／阻挡层／缓释层／金属。

In this paper. Si3N4has been joined successfully to 40Cr steel with amorphous Cu50Ti50B foil and ductile metal Ni interlayer by diffusion bonding at the first time. The experimental results showed that bonding time, temperature and thickness of Ni interlayer had influence on the strength of joint considerably. The optimum bonding parameters and thickness of Ni interlayer were 900℃. 40 min, 30 MPa and 1 mm, respectively. The analysis of microstructure of joint showed that the decrease of joining strength was due to the interaction between amorphous Cu50Ti50B and Ni interlayer, which reduced the activity of element Ti in the amorphous Cu50Ti50B foil and formed brittle intermetallics. The strength of joint was enhanced by using Mo insert-layer to restrain the interaction between amorphous Cu50Ti50B foil and Ni interlayer. New laminated interlayer model for diffusion bonding of ceramic to metal is proposed as follows:ceramic/active interlayer /isolation interlayer/ductile metal interlayer/metal