三孔双芯模挤压方管型材的金属流动行为分析

为了分析双芯模挤压铝型材时造成的流动不均匀以及模具结构对该类型材焊合质量的影响,采用DEFORM-3D有限元分析软件,对三孔双芯模挤压6005A铝合金方管型材的金属流动行为进行了分析.模拟结果表明,分流孔面积分布不均易造成方管型材镰刀弯缺陷,当中间分流孔与一侧分流孔的面积比值为0.93～1.03时,型材出口流速均匀、焊缝居中.焊合室高度为13～16mm时焊合良好、成形质量好.挤压力在坯料与焊合室底面碰触后急速上升,在突破模孔时达到最高值.型材出口温度受分流孔面积和焊合室高度影响较小,当坯料温度为480℃时,型材出口温度为546～548℃.在650吨卧式挤压机上进行了挤压实验,实验结果与仿真结果吻合.

Analysis of extrusion flow behaviors of square pipe deformed with three-porthole and two-core die

In order to reveal the nonuniform flow of aluminium in the two-core die and the effect of die structure on the welding quality,flow behavior of 6005A aluminium alloy square pipe was analyzed with DEFORM-3D. The tetrahedron mesh unit was adopted and the relative interference coefficient was set as 0. 4. The results show that,the weld line is centered in the side of square pipe when the area ratio of the middle porthole to the side porthole is between 0. 93 and 1. 03. When the height of welding chamber is equal to 13-16 mm, the alloy can be welded very well and the forming quality is the best. The extrusion force increases slowly as extruding,but it reaches the peak value abruptly when the billet touches the bottom of the welding chamber. The temperature of alloy increases obviously while the alloy breaks through the die bearing,and the peak value reaches 546-548 ℃. The extrusion experiment was carried out,and the results are in agreement with FEM results.