采用复合钎料钎焊Si3N4陶瓷

采用TiN／Ag—Cu—Ti复合钎料连接Si3N4陶瓷材料，采用扫描电镜观察了接头组织。TiN颗粒与Ag—cu组织结合紧密，并未与钎料基体进行反应，在钎缝中分布比较均匀，形成了局部金属基复合材料组织。由于颗粒与液态钎料之间能够形成较强的毛细作用，提高了活性元素Ti扩散的能力，Ti元素能够充分扩散到钎料与母材的界面上进行反应，生成一层致密的反应层。接头抗剪强度表明，在一定范围内，采用复合钎料可以明显提高接头强度。

Si3N4 ceramics brazing with composite soldering materials

Brazing of Si_3N_4 ceramics was achieved with composite soldering materials of Ag-Cu-Ti and TiN.SEM microstructures of joints showed that there was no reaction between TiN particulates and Ag-Cu eutectic matrix,but the interface between them was tight.The TiN particulates are generally homogeneous in the weld which is analogous to metal matrix composites.The diffusion ability of Ti is enhanced due to the strong capillary actions between the TiN particulates and the liquid Ag-Cu matrix alloy,which enables Ti to diffuse sufficiently to the interfaces between the brazing materials and the substrates,on which dense and solid reaction layers are formed.Shear results of joints show that joint strength can be increased obviously in a certain range with composite soldering materials.