圆柱体镦挤复合变形规律研究

摘要

针对镦挤复合成形过程中坯料在挤出时普遍存在的挤出高度不足的问题,利用Deform有限元软件模拟圆柱体自由端无约束时的镦挤复合成形过程,对镦挤成形过程的力学参数和变形规律进行分析;分别从理论和模拟两方面入手,研究正挤压和反挤压两种模式下的镦挤复合成形规律,模拟不同材料、不同挤出通道时的变形规律,绘制凸模行程与挤出高度曲线.研究结果表明:镦挤复合成形过程中的正挤压和反挤压具有一致的变形规律,当挤出通道直径为20~25 mm、摩擦因数为0.2~0.4时,适当地增大挤出通道直径和摩擦因数,均有利于提高坯料的挤出高度,当摩擦因数为0.35、挤出通道直径为25 mm时,坯料挤出高度最大.%For heading extrusion compound forming process of billet in common when it is squeezed out the problem of insufficient height,using the Deform software to simulate the cylinder free end unconstrained composite upsetting extrusion molding,for heading extrusion forming process was analyzed,the mechanical parameters and deformation law as well;respectively from two aspects of theory and simulation research.The extrusion and backward extrusion were studied under two different modes of upset compound forming law,to simulate different materials,to diameter of extrusion deformation law of channel,and drawing punch stroke and squeeze out the length of the curve.The research results show that the composite upsetting extrusion molding of extrusion and backward extrusion deformation law is consistent,when the extrusion channel diameter is in the range of 20-25 mm,the friction coefficient is in the range of 0.2-0.4,appropriately to lower the height of the billet diameter ratio,expanding extrusion channel diameter,increase all improve the extrusion billet high friction coefficient.When the friction coefficient is 0.35,the diameter of the extrusion channel is 25 mm,extrusion height is maximum.