AZ31B镁合金单点渐进热成形工艺的模拟优化

摘要

通过数值模拟研究了AZ31B镁合金在不同成形温度、压下量和进给速度下的单点渐进成形过程,建立了各参数与最大Mises应力和最大厚度减小率的响应面模型,并进行了以最大Mi-ses应力和最大厚度减小率为约束的多目标优化.结果表明:随着成形温度的升高,板料温升逐渐减小,当成形温度超过200℃后,板料不同位置的温度变化不大;各参数按对最大Mises应力和最大厚度减小率的影响由大到小排序为成形温度、进给速度、压下量;多目标优化得到的最佳工艺参数为成形温度273℃、压下量0.51 mm、进给速度1340 mm?min-1,在最佳工艺参数下模拟和实测成形件厚度的误差较小,证明了数值模型及响应面模型的准确性.%A single point incremental forming of AZ31B magnesium alloy,under different conditions of forming temperature,interlayer spacing and feed rate,were studied by numerical simulation.And then the response surface models showing the effects of the process parameters on the maximum Mises stresses and the maximum thickness reduction rates were established.Furthermore,a multi-objective optimization design was carried out with the maximum Mises stress and maximum thickness reduction rate as constraints.The results show that the temperature rise of sheet metal reduced with the increase of forming temperature.Especially when the forming temperature was over 200 ℃,the temperatures at different spots of the sheet metal changed little.The significance of the effects of the parameters on the maximum Mises stress or on the maximum thickness reduction rate were ranked from big to small as follows:forming temperature,feed rate and interlayer spacing.The optimal process parameters obtained by the multi-objective optimization were listed as follows:forming temperature of 273 ℃, interlayer spacing of 0.51 mm and feed rate of 1340 mm?min-1 .With the optimal process parameters,the errors between the simulated and measured thickness of the forming part were relatively small,indicating the accuracy of the numerical simulation model and the response surface model.