| 摘要: |
| 随着运载火箭结构轻量化发展，部分传统的钢结构逐渐被铝合金等轻质材料取代，这就涉及到铝/钢异种金属连接技术。为了获得高质量的铝/钢异质接头，利用自主研发的激光-感应加热复合焊接平台，开展了铝合金/不锈钢激光熔钎焊工艺试验。借助扫描电镜（SEM）、能谱分析仪（EDS）等分析手段，对比研究了有无感应加热条件下，铝/钢接头的宏观形貌、显微组织和力学性能。研究结果表明，感应加热能提高激光熔钎焊过程Zn-Al钎料在不锈钢表面的润湿铺展性增加了钎焊宽度，并促进了界面金属间化合物的生长；此外，感应加热提高了接头力学性能，单位长度拉伸载荷由189.8 N/mm增加到267.2 N/mm，接头断裂形式由界面附近的脆性断裂变化为熔合线附近的韧性断裂。 |
| 关键词: 感应加热；异种接头；激光焊接；微观组织 |
| 基金项目:国家自然科学基金（522***55、522***95）。 |
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| Mechanical Properties and Microstructure of Dissimilar Laser-induction Heating Hybrid Braze-welding of Al Alloy to Steel |
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Wu Lingqing1, Yang Jin1, Ying Chunzhi1, Ye Xin1, Wang Feifan2, Zhang Hua3
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1. School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620;2. Beijing Institute of Astronautical Systems Engineering, Beijing 100076;3. Shanghai Collaborative Innovation Center of Intelligent Manufacturing Robot Technology for Large Components, Shanghai 201620
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| Abstract: |
| With the development of lightweight launch vehicle structure, part of the traditional steel structure has been gradually replaced by aluminum alloy and other lightweight materials, which involves Al/Steel dissimilar joint technology. To obtain high-quality Al/Steel dissimilar joints, the self-developed laser-inductive heating composite welding platform was used to carry out the Al/steel laser braze-welding process experiment. With the help of a scanning electron microscope(SEM), energy spectrum analyzer(EDS), and other analytical means, the macroscopic morphology, microstructure, and mechanical properties of the aluminum/steel joints were comparatively studied with and without induction heating. The results show that induction heating can improve the wetting and spreading of Zn-Al brazing material on the surface of stainless steel which improved the brazing width and promote the growth of intermetallic compounds at the interface in the process of laser brazing welding; moreover, induction heating improves the mechanical properties of the joint, which are increased from 189.8 N/mm to 267.2 N/mm, and the form of fracture of the joint is changed from the brittle fracture near the interface to the ductile fracture near the fusion line. |
| Key words: induction heating；dissimilar joints；laser braze-welding；microstructure |
