Interfacial Structure and Formation Mechanism of Ultrasonic-assisted Brazed Joint of SiC Ceramics with Al—12Si Filler Metals in Air
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2017年第5期
论文作者：Xiaoguang Chen Ruishan Xie Zhiwei Lai Lei Liu Jiuchun Yan Guisheng Zou
文章页码：492 - 498
摘 要：Ultrasonic-assisted brazing of SiC ceramics was performed by filling with an Al—12Si alloy at a low temperature of 620 °C in air. The interfacial 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 SiO 2 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 Al2 SiO5 compounds formed at the interface between Al—12Si and a thicker SiO2 layer formed during the thermal oxidation treatment of the Si C ceramic. The SiO2 layer on the Si C ceramic did not hinder or impair the wetting and bonding process, and a stronger bond could form between Al—12Si and SiO2 or Si C in ultrasonicassisted brazing.
Xiaoguang Chen1,2，Ruishan Xie3，Zhiwei Lai2，Lei Liu2，Jiuchun Yan1，Guisheng Zou2
1. State Key Laboratory of Advanced Welding and Joining, School of Materials Science and Engineering, Harbin Institute of Technology2. Department of Mechanical Engineering, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Tsinghua University3. College of Material Science and Engineering, Taiyuan University of Technology
摘 要：Ultrasonic-assisted brazing of SiC ceramics was performed by filling with an Al—12Si alloy at a low temperature of 620 °C in air. The interfacial 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 SiO 2 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 Al2 SiO5 compounds formed at the interface between Al—12Si and a thicker SiO2 layer formed during the thermal oxidation treatment of the Si C ceramic. The SiO2 layer on the Si C ceramic did not hinder or impair the wetting and bonding process, and a stronger bond could form between Al—12Si and SiO2 or Si C in ultrasonicassisted brazing.
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