7075铝合金搅拌摩擦焊模拟与实验研究

搅拌摩擦焊解决了7075铝合金难焊接问题，但焊接过程中复杂的温度、流场变化容易造成焊缝缺陷.本文利用FLUENT软件模拟研究了7075铝合金焊接过程温度场与流场的变化规律，并对模拟结果进行了验证.结果表明:前进侧焊接温度高于后退侧，但其材料流速低于后退侧，焊缝最高温度出现在轴肩边缘内侧.搅拌头转速越大，焊接速度越小，则焊接温度越高;搅拌头转速越大，材料流速越快，焊接速度对材料流速影响越小.在本文实验条件下，在转速-焊接速度为800r/min-100mm/min 时，可得到无缺陷焊缝.

Experiment Study and Simulation for Friction Stir Welding Process of 7075 Aluminum Alloy

Friction stir welding (FSW) is used to solve the problem of the poor solderability of 7075 aluminum alloy. However， the complex changes of temperature and flow field are prone to cause defects. In this work， FLUENT software was used to study the changes of temperature and flow field of 7075 aluminum alloy during welding and the simulated results were verified. It is found that the temperature on the advancing side is higher， the flow rate is lower， and the maximum temperature appears inside the shoulder edge. When the rotation speed of the stirring head is higher， the welding speed becomes smaller， associated with a higher welding temperature. Meanwhile， the flow rate is faster and less affected by the welding speed. Under the conditions of the rotation speed-welding speed parameters of 800r/min-100mm/min，the defect-free weld can be achieved.