交变电场下SiC/Ti扩散连接过程中原子扩散和界面反应  

Atomic diffusion and interface reaction during diffusion bonding of SiC/Ti under alternating electric field

作　　者：孙东立[1] 张宁波[1] 王清[1] 李其海[1] 韩秀丽[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150090

出　　处：《哈尔滨工业大学学报》2016年第11期61-68,共8页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金(51172051)

摘　　要：为研究交变电场对界面处原子扩散行为及界面反应的影响,将交变电场引入SiC与Ti的扩散连接过程,采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射(XRD)及剪切性能测试等手段研究了交(直)流电场及电场强度对SiC/Ti扩散连接界面结构、原子扩散、剪切强度的影响,探讨了电场辅助扩散连接的物理机制.研究结果表明:在空洞闭合阶段,电压会使得界面处产生极大的镜像吸附力,使两个表面结合更加紧密,界面吸附力随着外加电压的增大和界面间距的减小而增大;在扩散反应阶段,施加电压会使界面处原子扩散通量增加,即外电压会促进SiC和Ti扩散连接界面处原子的扩散,电压越大,促进作用越明显.直流电压作用下扩散连接界面有正负极效应,而交流电压作用下无此效应.在950℃/1.5 h/7.5 MPa条件下施加400 V交流电压扩散连接接头强度达到63.8±9.4 MPa,界面反应层的相结构为SiC/Ti C/Ti C+Ti5Si3/Ti.电场可在一定程度上促进界面原子的扩散,提高连接效率.In order to obtain the influence of electronic on the diffusion behavior of atoms and interfacial reaction,diffusion bonding between SiC and Ti under alternating electric field was carried out. The influence of the intensity of AC（ DC） electric field on the interfacial microstructure,atomic diffusion and shear strength were characterized by means of scanning electron microscopy（ SEM）,energy disperse spectroscopy（ EDS）,X-ray diffraction（ XRD）and shear test. The mechanism of diffusion bonding under electric field was also discussed. The results showed that in the stage of pore closure interfaces contact tightly because of the great image interaction Image interaction increased obviously with the increase of voltage and decrease of interface distance. In diffusion reaction stage,the atom diffusion flux increased by applying voltage,illustrating that the applied voltage promoted the diffusion of the atom at SiC/Ti interface. The promoting effect was more obvious as the voltage increased. Electrodes effects existed in DC electric field while no electrodes effects existed in AC electric field. Under conditions 950 ℃/1. 5 h/7.5 MPa/400 V（ AC）,bonding Strength reached 63.8±9.4 MPa,and the order of structure of interface was SiC/Ti C/Ti C＋ Ti5Si3/Ti. Electric field promoted atomic diffusion to a certain extent and improved the efficiency of diffusion bonding.

关 键 词：扩散连接 SIC TI 界面 电场 

分 类 号：TG453.9[金属学及工艺—焊接]