厚板铝合金静止轴肩搅拌摩擦焊热过程及受力状态数值分析

基于Deform–3D软件建立了12mm板厚6061–T6铝合金静止轴肩搅拌摩擦焊接(Stationary Shoulder Friction Stir Welding,SSFSW)过程热力耦合数值模型,探讨了焊接工艺对SSFSW温度场、热循环及受力状态的影响规律。计算结果表明:焊接转速增加50%将引起焊核最高温度增加21.6%以上;焊接速度增加50%分别导致高温停留时间和冷却时间降低50%和60%以上;对给定转速1000~1500r/min及焊接速度100~150mm/min范围,静止轴肩的轴向力为28.2~24.3kN,前进阻力为17.4~15.3kN,焊接转速增加50%其轴向压力降低13.8%,焊接速度增加50%其前进阻力增加13.7%;搅拌针扭矩最高值在27.3~25N·m范围。上述数值模拟结果为厚板铝合金SSFSW搅拌工具设计及工艺优化提供重要理论依据。

Numerical Analysis of Stationary Shoulder Friction Stir Welding Process for Aluminum Alloy Thick-Plate

A thermo-mechanically coupled numerical model was developed to analyze the processes of stationary shoulder friction stir welded(SSFSW)AA6061–T6 aluminum alloy plate with a thickness of 12 mm based on the Deform-3D software.The effects of welding parameters on the temperature distribution,welding thermal cycling and bearing status of the tool in the welded joint were investigated.It was found that the 50%increase in rotational speed will cause the peak temperature of the nugget to increase more than 21.6%,and the 50%increase in welding speed will cause the high-temperature residence time and cooling time to decrease more than 50%and 60%,respectively.For given rotating speed in the range of 1000 r/min to 1500 r/min and welding speed in the range of 100 mm/min to 150 mm/min,the axial force of SSFSW is in the range of 28.2 kN to 24.3 kN and the forward resistance is in the range of 17.4 kN to15.3 kN;The maximum torque of tool pin is in the range of 27.3 N·m to 25 N·m.The 50%increase in rotating speed will reduce 13.8%axial force,the 50%increase in welding speed will increase 13.7%forward resistance.These numerical results mentioned above provide the important theoretical basis for the tool design and welding parameters optimum of SSFSW for aluminum alloy thick-plate.