【摘要】 采用Zr/Nb耐高温复合中间层 ,通过真空压力扩散焊连接SiC陶瓷和Ni基高温合金 (GH12 8) .研究了连接温度、连接压力和高温保温时间对试样连接强度的影响 .通过正交优选实验 ,确定出最佳工艺参数 :10 70℃ ,2 0min ,11.5MPa ,并根据此工艺制取了完整的陶瓷 /金属连接件 ,其抗弯强度达到了陶瓷母材强度的 5 2 % .微观结构研究表明 ,在界面处发生了元素的互扩散 ,生成了反应扩散层 ,实现了良好的冶金结合 ;同时 ,由于SiC陶瓷中存在开孔 ,从而中间层金属通过塑性流动进入空隙 ,形成机械咬合更多还原

【Abstract】 Joining of SiC ceramic to Ni_based superalloy (type GH128) has been realized by diffusion welding with Zr/Nb multiple interlayers. The effects of welding temperature, duration to keep the temperature and pressure for welding on bending strength of welded samples were studied. The optimized technical parameters including the temperature, the dwelling time and the pressure are 1 070 ℃ , 20 min and 11.5MPa respectively. Under these conditions, the bending strength of the welded sample is 52% of the bending strength of the SiC ceramic. In bending test, cracking of the welded sample occured partially at the SiC/Zr interface and partially in the ceramic near welding seam. These experimental results indicate that Zr/Nb multiple interlayers significantly relax the welding thermal stress generated due to the thermal mismatch of the dissimilar materials to be welded. The mechanism of bonding was investigated based on the observation of the microstructure and the determination of distribution of the elements at the welded area, which show that interdiffusions take place at the interfaces and contribute to bonding at the interfaces. In addition, mechanical bonding forms at Zr/SiC interface due to the penetration of Zr into the open pores of the SiC ceramic.更多还原