铝合金微型热管分流挤压模具变形分析与优化研究

Tool Deflection Analysis and Optimization of Porthole Die for Micro Heat Pipe in Aluminum Alloy

研究铝合金微型热管这类微型复杂空心挤压型材极易产生内腔偏心缺陷的问题,提出相应的挤压模具的结构设计原则。基于Altair Inspire Extrude Metal有限元分析软件,分析挤压比、焊合室高度、模芯间距和工作带长度对模芯变形的影响规律。模拟结果表明,焊合室高度和模芯间距对模芯变形的影响比较显著,而挤压比和工作带长度影响微弱。当焊合室高度提高至某一阈值时,模芯的最大变形量随着焊合室高度增加。模芯间距存在最优值,偏离该值会促进模芯变形。挤压试验结果表明,在较优的模具结构参数下获得壁厚尺寸精度±0.04mm的微型热管型材,对应的主要模具结构参数为挤压比137、模芯间距28 mm、焊合室高度8 mm和工作带长度3 mm。

The problem of cavity eccentricity of micro complex hollow extruded profiles such as micro heat pipes in aluminum alloy is investigated,and the corresponding principle of structural design in porthole die is proposed.The influences of extrusion ratio,welding chamber height,die core spacing and bearing length on the die core deflection are analyzed using Altair Inspire Extrude Metal finite element analysis software.The simulation results show that the influences of welding chamber height and die core spacing are significantly evident,whereas the influences of extrusion ratio and bearing length are weak.The maximum deformation of the die core increases with welding chamber height when it increases to a certain threshold.There is an optimum value for die core spacing,deviations from this value would promote die core deformation.The experimental results show that the micro heat pipe profile with a wall thickness dimensional accuracy of±0.04 mm is obtained under the better die structure parameters.The corresponding main die structure parameters are extrusion ratio of 137,die core spacing of 28 mm,welding chamber height of 8 mm and bearing length of 3 mm.