基于数值模拟的搅拌摩擦焊晶粒分析

Grain Analysis of Friction Stir Welding Based on Numerical Simulation

在Al-Zn-Mg合金的搅拌摩擦焊接(FSW)期间,焊接材料的晶粒尺寸显著影响其机械性能。为了预测不同焊接工艺参数对焊接材料晶粒尺寸的影响规律,本文使用DEFORM-3D软件模拟了搅拌摩擦焊接过程,分析不同的旋转速度和不同的焊接速度对搅拌区(SZ)温度场和应变率场的影响。结果表明,SZ的温度随焊接速度增加而降低,但焊接速度对应变率没有影响;SZ的温度和应变率随着搅拌针旋转速度的增加而增加。借助Zener-Hollomon参数的经验公式预测的晶粒尺寸和实验得出的SZ晶粒尺寸变化趋势一致,发现SZ的晶粒尺寸随着旋转速度增加而增加,随焊接速度增加而变小。

During friction stir welding(FSW)of Al-Zn-Mg alloy,the grain size of the welded material significantly affects its mechanical properties.In order to predict the influence of different welding process parameters on the grain size of the welded material,the DEFORM-3D software was used to simulate the FSW process,and the effects of different rotation speed and different welding speed on the temperature field and strain rate field of the stirring zone(SZ)were analyzed.The results show that the temperature of SZ decreases with the increase of welding speed,but the welding speed has no effect on the strain rate.The strain rate and temperature of SZ increase as the rotating speed increases.The grain size predicted by the empirical formula of the Zener-Hollomon parameter is consistent with the variation trend of SZ grain size obtained by experiments.It is found that the grain size of SZ increases with the increase of the rotation speed,and it becomes smaller when the welding speed increases.