钎焊温度对Ti60合金与Si_3N_4陶瓷接头界面组织及性能的影响

Effect of brazing temperature on interfacial microstructure and properties of Ti60/Si_3N_4 brazed joints

为研究钎焊温度对Ti60/Si_3N_4接头组织与力学性能的影响,采用Ag-28Cu共晶钎料在870~910℃温度区间,保温10 min条件下进行钎焊连接.利用扫描电子显微镜、能谱仪对钎焊接头界面组织进行分析,得到的典型接头界面组织结构为Ti60/Ti-Cu化合物/Ag(s,s)+Cu(s,s)/Ti-Cu化合物/Ti5Si3+TiN/Si_3N_4,并对钎焊接头的组织演变过程进行了分析.结果表明,随着钎焊温度的升高,Ti60侧的Ti-Cu化合物反应层与Si_3N_4陶瓷侧的Ti5Si3+TiN反应层厚度逐渐增加,Ag(s,s)与Cu(s,s)含量减少,同时,扩散至Si_3N_4陶瓷侧的Ti元素与液相中Cu元素反应生成Ti-Cu化合物并在Ti5Si3+TiN反应层中形核.剪切测试表明,在钎焊温度880℃,保温10 min工艺参数条件下获得的接头最大抗剪强度为61.7 MPa.

In order to study the effect of brazing temperature on the microstructure and mechanical properties of Ti60/Si3N4 joints,Ag-28Cu eutectic alloy was used to braze Ti60 alloy and Si3N4 ceramic at the temperature range from 870°C to 910°C for 10 min.The microstructure of the brazed joint was analyzed by Scanning Electron Microscope and Energy Dispersive Spectrometer.The typical interfacial microstructure was Ti60/Ti-Cu intermetallic layer/Ag(s,s)+Cu(s,s)/Ti-Cu intermetallic layer/Ti5Si3+TiN/Si3N4.The evolution process of the brazed joint was analyzed.The results showed that the thickness of Ti-Cu intermetallic layer next to Ti60 alloy and the Ti5Si3+TiN layer on Si3N4 ceramic side increased gradually with the increasing of brazing temperature.Meanwhile,the content of Ag(s,s)and Cu(s,s)decreased.In addition,Ti-Cu compound was formed in Ti5Si3+TiN layer by the reaction between element Ti which diffused to Si3N4 ceramic side and element Cu in the liquid phase.The shear test indicated that the highest shear strength of 61.7 MPa was obtained with the brazing technological parameter of 880°C+10 min.