连续挤压铜扁排的阻流角设计及物理场分布

Design of choked flow angle of die and distribution of physical field of copper flat line produced by continuous extrusion

基于Deform-3D平台,建立了Conform连续挤压生产大宽厚比铜扁排有限元模型,研究了连续挤压过程中阻流角变化对模具出口处金属流动及相应应力场分布的影响规律,并结合方差分析法获得了模具出口处的流速均方差,观察模具阻流角对扁排成型的影响.研究表明：模具阻流角从3°~15°变化时,随着阻流角的增加,金属流速均方差先增大后减小,其阻流角区域等效应力值以及模具入口处沿挤压方向应力也逐渐增加;在定径带长度一定以及模具载荷允许的情况下,选择3°、5°、15°的阻流角可使模具出口处金属流速相对稳定,扁排成形性较好;当模具容易损坏时,选择3°和5°阻流角既可降低模具载荷又可获得板形均匀的扁排.

Based on software Deform-3D,The finite element model（ FEM） for big flakiness ratio produced by conform continuous extrusion is established. This paper studies the metal flow at the exit of die and stress field＇s distribution with a variety of the choked flow angle during the process of conform continuous extrusion. The mean-square deviation of velocity at the exit of die can be gotten by analysis of variance,which is used for obtaining the effect of the choked flow angle on the formed of copper flat line. The results as follows： When choked flow angle of die changed from 3°to 15°,the mean square deviation of metal flow velocity increased at first and then decreased with angle increasing,at the same time,equivalent stress in the area of the choked flow angle and the stress across the extrusion direction at the entrance of die would be also increased. With a certain length of calibrating and under die loading,the choked flow angles at 3°,5°and 15°can make metal flow velocity relatively stable at the die exit. When die damages easily,the choked flow angle of 3° and 15° can not only reduce die loads,but also get copper flat line which have homogeneous plate shape. The result could provide theoretical basis for the study of the continuous extrusion process and the optimization of technical parameters.