摘要
目的研究铝合金与镀锌钢板回填式搅拌摩擦点焊界面组织演变机制与焊接工艺参数对力学性能的影响规律。方法采用连续焊接和改变焊接工艺参数的方法,分析了焊具自摩擦对焊接温度和接头力学性能的影响。采用电镜研究了铝合金与镀锌钢板连接界面的显微组织分布和焊接工艺参数对焊接温度及接头力学性能之间的内在关系。结果焊具的自摩擦及重复性预热影响焊具温度和接头力学性能,其作用远大于焊接工艺参数的影响。镀锌层阻止了被焊材料的直接接触而避免了大量金属间化合物的形成,镀锌层和铝合金反应生成固溶体组织,从而提高了铝合金与钢的焊接性。此外,液态的锌被挤出搅拌区,形成钎焊的连接机制,增大了接头连接面积和强度。最佳焊接工艺参数为:旋转频率1800 r/min,套筒下压量1.0 mm,停留时间3 s。在此焊接规范下,接头最大接头剪切强度为6.23 kN,且76.2%的焊点力学性能满足工业使用标准。结论回填式搅拌摩擦点焊是实现铝合金与镀锌钢板高质量连接的可靠方式。
The paper aims to research the interface microstructure evolution of aluminium alloy/zinc coated steel refill friction stir spot welding and the influence rule of welding parameters on mechanical properties. The influence of tool’s self-friction on welding temperature and mechanical property of joint was analyzed by continuous welding and changing welding parameters. The result indicated that self-friction of the tool and repeat pre-heating significantly affected the tool temperature and weld performance. Its influence was much higher than that of the welding parameters. The zinc coating layer prevented direct contact of Al and Fe and thus avoided the formation of bulk IMCs. Reaction between zinc coating materials and aluminum alloy materials produced a layer of eutectic layer and thus improved the weldability of aluminum alloy and steel. In addition, the liquid zinc was squeezed out of the stir zone, and thus formed the connectionism brazing and improved the bonding area and weld strength. The optimized welding parameter was rotational speed of 1800 r/min, penetration depth of 1.0 mm and dwell time of 3 s. Under this weld specification, the maximum lap shear strength can reach 6.23 kN, and the mechanical property of 76.2% weld can meet the industrial requirement. Refill friction stir spot welding is a reliable way for high quality connection of aluminum alloy and zinc coated steel.
作者
申志康
刘小超
陈海燕
李文亚
DING Yuquan
CHEN James
GERLICH Adrian
SHEN Zhi-kang;LIU Xiao-chao;CHEN Hai-yan;LI Wen-ya;DING Yuquan;CHEN James;GERLICH Adrian(Shaanxi Key Laboratory of Friction Welding Technologies,State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi'an 710072,China;Centre for Advanced Materials Joining,University of Waterloo,Waterloo N2l 3G1,Canada;Canmet MATERIALS,Natural Resources Canada,Hamilton,L8P 0A5,Canada)
出处
《精密成形工程》
2019年第6期42-46,共5页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(51975479)
中央高校基本科研业务费专项资金(3102019QD0404)
关键词
回填式搅拌摩擦点焊
铝合金
镀锌钢板
连接机制
力学性能
Refill friction stir spot welding
aluminum alloy
zinc coated steel
joining mechanism
mechanical property
