工艺参数和支撑方式对镁合金方锥件单点渐进成形负回弹和壁厚的影响

Effect of process parameters and support modes on negative springback and wall thickness of single-point progressive forming of magnesium alloy square conical parts

研究了AZ31B镁合金方锥件的侧壁负回弹问题和成形件壁厚问题。针对侧壁负回弹部分设计了4因素3水平正交实验,通过机床实验研究了成形角、成形温度、下压量和成形高度对成形件侧壁负回弹量的影响程度,并通过数值模拟进行验证。结果表明,对方锥件侧壁负回弹量的影响程度从高到低分别为:成形角、下压量、成形温度、成形高度。仿真结果和机床实验结果均表明负回弹段是影响成形件回弹的重要部分。仿真结果还表明:不同的支撑方式对成形件的壁厚分布有重要影响,下压板伸出方式下的侧壁壁厚比下压板未伸出方式下的壁厚被减薄的更加均匀,壁厚极差较小;下压板伸出方式可有效减小负回弹段的回弹值。

Negative side wall springback and wall thickness of AZ31 B magnesium alloy square conical parts were studied.Orthogonal test with four factors and three levels was designed for the negative springback of the side wall.Firstly,the influence of forming angle,forming temperature,pressure amount and forming height on the negative springback of the side wall of the formed part was studied through the machine tool processing experiment,which was verified by numerical simulation.The results show that the influence degree of negative springback on the side wall of square conical parts from high to low is forming angle,pressure amount,forming temperature and forming height.Both simulation results and machine tool experimental results show that the negative springback section is an important part that affects the springback of forming parts.The simulation results also show that different support modes have important impact on the wall thickness distribution of forming parts.The side wall thickness under the extension mode of the lower pressure plate is more uniform than that under the non-extension mode of the lower pressure plate,and the wall thickness difference is smaller.The springback value of the negative springback section can be effectively reduced by the extension mode of the lower pressure plate.