工艺参数对AZ31B镁合金单点渐进翻边精度的影响

目的 以AZ31B镁合金板为研究对象，研究初始成形角、工具直径、成形温度及层间距对单点渐进圆孔翻边精度的影响规律。方法 使用有限元软件对2 mm厚的镁合金板材进行数值模拟，通过计算翻边直壁处的平均回弹量，得出不同工艺参数对单点渐进圆孔翻边直壁轮廓的影响规律。通过正交实验分析了交互作用下工艺参数对圆孔翻边直壁处平均回弹量的影响，通过极差分析确定了最优工艺参数组合，并通过实验对所得结果进行了验证。结果 随着初始成形角的增大、工具直径的增大、成形温度的升高及层间距的减小，圆孔翻边制件直壁处的成形精度提高，各因素按影响程度由大到小的顺序依次为:成形温度、初始成形角、工具直径和层间距。成形精度最高的工艺参数组合如下:初始成形角为30°、工具直径为10 mm、成形温度为275 ℃、层间距为0.5 mm。结论 采用仿真模型模拟单点渐进圆孔翻边过程具有较高的准确性，使用优化后的工艺参数得到翻边零件直壁区域的最小厚度以及平均回弹量与仿真结果误差均在3%以内，升高温度可以明显提高单点渐进圆孔翻边的制件精度。

Effect of Process Parameters on Flanging Accuracy of AZ31B Magnesium Alloyin Single Point Incremental Process

The work aims to take AZ31B magnesium alloy sheet as the object to study the effects of initial forming angle, tool diameter, forming temperature, and layer spacing on the flanging accuracy of the round hole in single point incremental forming. The finite element numerical simulation method was used to analyze the 2 mm thick magnesium alloy sheet, and the effect of different process parameters on the straight wall profile of the round hole flanging was obtained by calculating the average springback value. The effect of process parameters under the interaction on the average springback at the straight wall of the flanging was analyzed by an orthogonal experiment. The optimal combination of process parameters was determined by range analysis, and the results were verified by experiments. With the increase of the initial forming angle, tool diameter and forming temperature and the decrease of the layer spacing, the flanging accuracy increased, and the importance of parameters in a descending order was as follows:forming temperature, initial forming angle, tool diameter, and layer spacing. The combination of process parameters with the highest forming accuracy included the initial forming angle of 30°, tool diameter of 10 mm, forming temperature of 275 ℃, and layer spacing of 0.5 mm. The simulation model has a high accuracy for simulating the single point incremental flanging process. The profile error of the flanging by the optimal combination of process parameters between the physical experiments and the simulation results is less than 3%. The elevated temperature can significantly improve the flanging profile accuracy of the round hole.