Interfacial Structure and Formation Mechanism of Ultrasonic-assisted Brazed Joint of SiC Ceramics with Al—12Si Filler Metals in Air  

作　　者：Xiaoguang Chen Ruishan Xie Zhiwei Lai Lei Liu Jiuchun Yan Guisheng Zou 

机构地区：[1]State Key Laboratory of Advanced Welding and Joining, School of Materials Science and Engineering, Harbin Institute of Technology [2]Department of Mechanical Engineering, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Tsinghua University [3]College of Material Science and Engineering, Taiyuan University of Technology

出　　处：《Journal of Materials Science & Technology》2017年第5期492-498,共7页材料科学技术（英文版）

基　　金：the financial support for this project from the China Postdoctoral Science Foundation (No.2015M570093);the National Natural Science Foundation of China (Nos. 51435004 and 51075104);the State Key Lab of Advanced Welding and Joining Harbin Institute of Technology (No. AWJ-M14-05)

摘　　要：Ultrasonic-assisted brazing of SiC ceramics was performed by filling with an Al-12Si alloy at a low tem- perature of 620 ℃ in air. The interracial characteristics and formation mechanism were investigated. The joint shear strength reached 84-94 MPa using the ultrasonic time of 2-16 s. The fracture morphology showed that the fracture path initiated and propagated in the joint alloy. The thin film of amorphous SiO2 that formed on the SiC surface was non-uniformly decomposed and diffused into the liquid Al-12Si alloy under the cavitation erosion effect of ultrasound. Abnormal isolated blocks of A12SiO5 compounds formed at the interface between Al-12Si and a thicker SiO2 layer formed during the thermal oxidation treatment of the SiC ceramic. The SiO2 layer on the SiC ceramic did not hinder or impair the wetting and bonding process, and a stronger bond could form between Al-12Si and SiO2 or SiC in ultrasonic- assisted brazing.Ultrasonic-assisted brazing of SiC ceramics was performed by filling with an Al-12Si alloy at a low tem- perature of 620 ℃ in air. The interracial characteristics and formation mechanism were investigated. The joint shear strength reached 84-94 MPa using the ultrasonic time of 2-16 s. The fracture morphology showed that the fracture path initiated and propagated in the joint alloy. The thin film of amorphous SiO2 that formed on the SiC surface was non-uniformly decomposed and diffused into the liquid Al-12Si alloy under the cavitation erosion effect of ultrasound. Abnormal isolated blocks of A12SiO5 compounds formed at the interface between Al-12Si and a thicker SiO2 layer formed during the thermal oxidation treatment of the SiC ceramic. The SiO2 layer on the SiC ceramic did not hinder or impair the wetting and bonding process, and a stronger bond could form between Al-12Si and SiO2 or SiC in ultrasonic- assisted brazing.

关 键 词：Ultrasonic Brazing Ceramic Interface Cavitation erosion 

分 类 号：TG454[金属学及工艺—焊接] TQ174.6[化学工程—陶瓷工业]