电场作用下SiC与Ti扩散连接界面结构及力学性能

Microstructure and Mechanical Properties of SiC/Ti Diffusion Bonding Joints under Electric Field

对电场作用下Si C与Ti扩散连接接头界面结构及力学性能进行了分析测试。研究发现,当金属、陶瓷分别连接电场正、负极时,电场可促进界面扩散反应层厚度增加,而电压极性相反时,促进作用明显减弱;连接界面发生原子扩散及化学反应,生成相主要为:Ti_5Si_3与Ti C,从Si C侧到Ti侧界面相结构依次为Si C/Ti C/(Ti_5Si_3+Ti C)/Ti;性能测试结果表明,1000℃/2 h/7.5 MPa下获得的接头剪切强度为66.4 MPa,950℃/1.5 h/7.5 MPa/400 V电场作用下扩散连接接头剪切强度为69.6 MPa,即在其他连接工艺参数相同情况下,施加电压可以增大剪切强度,提高连接效率。

The diffusion bonding of SiC to Ti under electric field was carried out,and the microstructure and mechanical properties of Si C/Ti diffusion bonding joints were investigated.Results show that when the metal and ceramic connect the positive and negative of the electric field,respectively,the electric field will increase the thickness of interface diffusion layer,but reversed connection can weaken the promotion of interface diffusion layer thickening significantly.Atom diffusion and reactions occur at the SiC/Ti interface,new phases generated at the interface are mainly Ti_5Si_3 and Ti C,and the interface structure from Si C to Ti is SiC/TiC/（Ti5Si3＋Ti C）/Ti.Mechanical properties testing results show that the shear strength of the joint at 1000 ℃2 h/7.5 MPa is 66.4 MPa,but the shear strength of the joint at 950 ℃/1.5 h/7.5 MPa/400 V is 69.6 MPa.Therefore,applying voltage during the bonding process can increase the shear strength and improve the efficiency of the bonding.