(1. 北京科技大學 新材料技術(shù)研究院，北京 100083；
2. 內(nèi)蒙古工業(yè)大學 材料科學與工程學院，呼和浩特 010051)
摘 要: 基于Deform-3D有限元分析平臺，采用所開發(fā)的焊合過程網(wǎng)格重構(gòu)技術(shù)，分析方形管分流模雙孔擠壓時焊合室深度及焊合角對成形質(zhì)量的影響。結(jié)果表明：焊合面平均靜水壓力、分流橋底部等效應力及模芯最大偏移量隨焊合室深度的增加而增加；綜合考慮焊合質(zhì)量、模具應力集中及型材尺寸精度等因素，分流模合適的焊合室深度為10~16mm；隨著焊合角的增加，焊合室內(nèi)死區(qū)體積及擠壓力均增大，而模芯最大變形偏移量呈減小趨勢；綜合考慮焊合角對擠壓過程死區(qū)大小、模芯的穩(wěn)定性及擠壓力大小的影響，分流模合適的焊合角為30˚~45˚。實驗結(jié)果和模擬結(jié)果在金屬流動景象、死區(qū)位置、死區(qū)形狀等方面吻合較好。
關(guān)鍵字: 有限元模擬；分流模擠壓；焊合室深度；焊合角
quality of extrusion of square tube by porthole die
（1. Advanced Materials and Technologies Institute, University of Science and Technology Beijing, Beijing 100083, China;
(2. School of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhat 010051, China）
Abstract:Adopting commercial FEM soft Deform-3D and welding mesh reconstruction method, the influences of welding chamber depth and welding angle on forming quality of diplopore extrusion of square tube by a porthole die were analyzed. The results show that, the hydrostatic stress of welding plane, equivalent stress on the bottom of flow-separating bridge and maximal offset of die mandrel increase with increasing the welding chamber depth. Comprehensively considering the factors of welding quality, stress concentration of die and size-precision of the profile, the reasonable welding chamber depth of the porthole die is from 10mm to 16mm. With the welding angle increasing, the dead zone volume in welding chamber and the extrusion force increase, but the maximal offset of the die mandrel decreases. Comprehensively considering the influences of welding angle on the dead zone during extrusion, the stability of die mandrel and the extrusion force, the reasonable welding angle of the porthole die is from 30° to 45°. The experimental and simulation results agree well in the metal flow, position and shape of dead zone.
Key words: finite element simulation; porthole-die extrusion; welding chamber depth; welding angle
