焊合角和焊合室深度对复杂悬臂空心铝型材挤压成形质量的影响

应用Hyper Xtrude有限元分析软件,考察了带长悬臂结构空心截面铝型材挤压时的焊合角α和焊合室深度h对其挤压成形质量的影响。结果表明:当α在15°~45°时,型材悬臂处及空心部位四周分流桥下金属的流动速率较大,开始焊合的时间早,焊合历程长;当α增加到60°时,相应区域金属的流动速率明显降低,焊合推迟;在α达到90°时,该情况最为严重,焊合历程变短。α为45°时,模芯最大偏移量达到最小值0.045 mm。随着h的增加,焊合面静水压力最小值与上模最大等效应力及模芯最大偏移量均逐渐增大。综合考虑各因素的影响,确定该型材挤压模具的最佳焊合角和焊合室深度分别为45°与20 mm,并将其用于挤压模具设计,试模发现模拟结果与试模结果吻合较好,挤出型材的综合质量较高。

Influences of welding angle and welding chamber depth on the extrusion quality of hollow aluminum profile with complex cantilever

Based on finite element analysis software HyperXtrude,the influences of welding angle α and welding chamber depth h on extrusion forming quality for a hollow section aluminum profile with long cantilever structure were investigated.The results indicate that the metal flow velocity under port bridges around profile cantilever and hollow section is high,and the metal welding starts early and has a long time when α ranges from 15° to 45°.Then,the metal flow velocity of corresponding region decreases obviously and the metal welding delays when α is up to 60°.While it becomes the most serious when α increases to 90°,and the metal welding time becomes short.Meanwhile,the maximum offset of mandrel reaches the minimum values 0.045 mm when α is 45°.Furthermore,the minimum hydrostatic pressure on the welding plane,the maximum equivalent stress of upper die and the maximum offset of mandrel have the similar incremental trends with the increase of welding depth h.The optimal welding angle of 45° and welding chamber depth of 20 mm were determined by considering influences of each factor comprehensively.According to the optimal scheme,the extrusion die is designed.It is found that the simulation results and the experimental results fit well by extrusion trial,and the comprehensive quality of the extruded profile is high.