摘要
以3 mm厚的碳素结构钢Q235与3 mm厚的2A12铝合金为基材,通过机械加工的方式沿厚度方向将钢端面加工成倾斜的锯齿形状,运用搅拌摩擦偏心焊完成钢和铝异种金属的连接,以异种金属的对接焊接接头为研究对象。从焊缝宏观组织可以看到,在搅拌针的搅拌与轴向顶锻力的共同作用下,锯齿顶部的钢发生软化并随搅拌针的搅拌迁移到铝基体中。运用XRD分析表明,结合界面处除了铁和铝之外,还形成了Fe Al、Fe Al2等金属间化合物,靠近铝侧的焊缝显微硬度比铝母材的硬度要高,原因是形成的金属间化合物使得其硬度增高,通过扫描电镜与元素能谱分析,锯齿的底部铝钢结合界面形成了一层比较薄的过渡层,铝钢接头以冶金和机械结合的方式为主。
3 mm thick low carbon steel set as raw materials. The steel section was Q235 and 3ram thick aluminum alloy 2A12 were machined into an inclined and serrated shape a- long the thickness direction. Al-steel dissimilar metals were joined with the eccentric friction stir welding （FSW）. The experiment was carried out on the butt joint of Al-steel dissimilar metals. From the aspect of the weld macrostructure,the steel at the top of the serrated shape is softened and moved to the aluminum matrix with the stirring pin under the stirring function of the pin and the axial upsetting force. XRD analysis also shows that FeA1 and FeA12 inter- metallic compounds are formed in addition to iron and aluminum existing in the jointing inter- face. Due to the formed intermetallic compounds in the interface, the micro-hardness of the weld near aluminum side is higher than that of aluminum base material. After investigation with scanning electron microscope and the element energy spectrum analysis, it is found that a layer of relatively thin transition layer is formed at the serrated bottom of Al-steel interface, and Al-steel joints are mainly combined by the metallurgy and mechanical combination mode.
出处
《轻合金加工技术》
CAS
北大核心
2017年第4期36-40,共5页
Light Alloy Fabrication Technology
基金
国家自然科学基金资助项(51265030)
甘肃省自然科学基金(2014GS03264)
关键词
搅拌摩擦焊
Q235钢
偏心焊
锯齿状
连接机制
friction stir welding
Q235 steel
eccentric welding
serrated shape
joint mechanism
