基于有限体积法的铜母线连续挤压扩展成形的数值模拟

对连续挤压几何模型进行简化,基于MSC.SuperForge软件平台,成功实现10mm×80mm铜母线连续挤压扩展成形的有限体积数值模拟,避免了刚塑性有限元法模拟大变形需要多次网格重划,体积损失等难题。获得了金属在模腔内的流动-应力-温度-组织耦合变化规律,详尽的分析了整个扩展变形流动过程与各物理场之间的关系,进一步探明了模腔结构对成形过程的影响。结果表明,在成形过程中,坯料最高温度约为872K,出现在坯料与挡料块接触的表面上;当趋于稳定状态时,扩展腔内坯料温度分布比较均匀一致,约为660K;坯料密度发生了明显变化,镦粗段坯料密度最高,为8.962×103kg/m3,产品成形区域坯料密度最低,在8.750×103kg/m3~8.771×103kg/m3之间。在镦粗段内,坯料与挤压轮的打滑量为32%,在镦粗前,坯料与挤压轮保持同步。坯料作用在腔体上的压力高点出现在腔体挡料块顶端,压力为473MPa。扭矩校核表明,数值模拟结果和实测结果吻合较好。

Numerical simulation of continuous extrusion extending forming for copper bus-bar based on finite volume method

By simplifying the geometrical model of continuous extrusion,FVM simulation of continuous extrusion extending forming process for copper bus-bar 10mm×80mm was successfully realized based on MSC.Superforge software,the difficulties,such as grid distortion and remeshing and volume loss faced by simulation of large deformation with traditional rigid-plastic FEM,are effectively avoided.The metal flow-stress-temperature-tissue coupling variety laws are obtained,and the relationships between them and real deformation are analyzed in detail,and the effects of chamber structure on forming process are further explored.The results show:In the forming process,the highest temperature of billet is about 872K,it occurs on the contacting surface between billet and abutment;when the process approaches stable state,temperature distribution of billet in extending chamber is comparatively even,at the level of 660K;the density of billet are changed obviously,the highest density is in upsetting zone,being up to 8.962×103kg/m3,the lowest density is in forming zone of product,ranging from 8.750×103kg/m3 to 8.771×103kg/m3;in the upsetting zone,the skid quantum between billet and extrusion wheel is 32%,before the billet is upset,they keep synchronization;the maximum value of pressure that billet acts on the chamber occurs on the top section of abutment,being up to 473MPa.The test check of torque indicated the results of simulation tally with tested results perfectly.