回填时间对RFSSW接头断裂行为的影响

发布时间：2018-06-13 08:48

  本文选题：回填式搅拌摩擦点焊 + LY铝合金　； 参考：《焊接学报》2017年05期

【摘要】：为研究回填时间对回填式搅拌摩擦点焊接头断裂模式和断裂机理的影响,对上下板厚度分别为1.5 mm和2 mm的LY12铝合金板材进行了点焊试验,并对焊后接头进行拉剪试验.结果表明,当回填时间较短时,套筒作用区与热力影响区间界面上的原子扩散效果差,甚至在近表面附近出现开裂,导致接头的剪切-塞型断裂.当回填时间足够长时,焊接接头的断裂模式转化为剪切断裂,裂纹主要沿着上下板搭接面扩展.同时,显微结构、硬度与断口形貌的试验结果验证了文中对断裂机制的解释.
[Abstract]:In order to study the effect of backfilling time on fracture mode and fracture mechanism of backfill friction stir spot welding joint, spot welding tests were carried out on LY12 aluminum alloy sheet with upper and lower plate thickness of 1.5 mm and 2 mm respectively, and tensile and shear tests were carried out on the joint after welding. The results show that when the backfill time is relatively short, the atomic diffusion effect on the interface between the sleeve interaction zone and the thermal influence zone is poor, and even cracking occurs near the surface, which leads to the shear-plug fracture of the joint. When the backfill time is long enough, the fracture mode of welded joint is transformed into shear fracture, and the crack mainly propagates along the lap joint of upper and lower plates. At the same time, the experimental results of microstructure, hardness and fracture morphology verify the explanation of fracture mechanism in this paper.
【作者单位】： 沈阳航空航天大学航空航天工程学部;北京航空航天大学机械工程及自动化学院;
【基金】：国家自然科学基金资助项目(51204111) 辽宁省自然科学基金资助项目(2014024008)
【分类号】：TG407
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本文编号：2013431