直流电热冲击辅助多组分氧化物钎焊SiC陶瓷的工艺及性能  

Process and properties of SiC brazing through multicomponent oxide assisted by electrothermal shock

作　　者：闫耀天 刘柏深 曹健[1] 亓钧雷[1] YAN Yaotian;LIU Baishen;CAO Jian;QI Junlei(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]哈尔滨工业大学,先进焊接与连接国家重点实验室,哈尔滨150001

出　　处：《焊接学报》2022年第11期22-29,I0004,共9页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(52175303);黑龙江省“头雁”团队经费资助(HITTY-20190013);黑龙江省高等教育教学改革研究项目(SJGZ20190019)。

摘　　要：开发了一种直流电热冲击辅助高温钎焊新技术,成功实现了18.77Gd_(2)O_(3)−4.83Y_(2)O_(3)−28.22TiO_(2)−8.75ZrO_(2)−39.43Al_(2)O_(3)多组分氧化物钎料与SiC陶瓷母材之间的钎焊连接.加热元件采用碳纤维编织体,在20 A直流电流及800 W截断功率下,实现了最佳剪切强度为136.27 MPa的SiC钎焊接头.多组分氧化物钎料中Al_(2)O_(3)及TiO_(2)组分对实现良好的SiC陶瓷钎焊接头至关重要,其中TiO_(2)组分与SiC在高温下发生反应从而在界面处生成厚度约为10μm的富Ti界面反应层,Al_(2)O_(3)相向母材中渗入而形成的枝状通道起到钉扎效果,有利于提升钎焊接头整体强度.热输入过大时,SiC母材严重分解,大量C元素向钎缝区扩散,导致钎缝区出现明显裂纹缺陷,剪切强度降低至约60 MPa,断裂完全发生于钎缝区.An electrothermal shock-assisted high-temperature brazing technology was proposed in this work,which successfully achieved the joining of 18.77Gd_(2)O_(3)-4.83Y_(2)O_(3)-28.22TiO_(2)-8.75ZrO_(2)-39.43Al_(2)O_(3) multicomponent oxide filler and SiC ceramics.The SiC brazed joint with an optimal shear strength of 136.27 MPa was achieved under 20 A DC current and 800 W cut-off power by using carbon fiber as the heating element.The Al_(2)O_(3) and TiO_(2) components in the multi-component oxide filler metal were very important to achieve a good SiC ceramic brazing joint.TiO_(2) reacted with SiC at high temperature to generate a Ti-rich interfacial reaction layer with a thickness of~10μm at the interface,and Al_(2)O_(3) penetrated into the base metal to form a pinning effect,which was beneficial to improve the brazed joint strength.However,when the heat input was too large,the SiC base metal would decompose seriously,and a large amount of C element would diffuse to the brazing seam,resulting in obvious crack defects.The shear strength would be reduced to~60 MPa,and the fracture completely occurred in the brazing seam.

关 键 词：直流电 热冲击 高温钎焊 SIC陶瓷 多组分氧化物 

分 类 号：TG454[金属学及工艺—焊接]