【摘要】 采用Deform-3D有限元软件对大型等通道转角压(Equal channel angular pressing,ECAP)进行动态计算仿真模拟,并进行试验研究,重点考察变形体与模具间摩擦因数和模具水平通道扩口直径对挤压载荷的影响。模拟结果表明,剪切摩擦模型适合用于ECAP变形仿真模拟计算,摩擦因数对大型ECAP的最大挤压载荷具有很大影响,随着摩擦因数的增加,最大挤压载荷急剧增加;摩擦因数μ=0.6(近似于铝和钢干摩擦)时的挤压载荷是摩擦因数为0时挤压载荷的5.1倍;增加出口通道扩口端的直径,当μ<0.6时,对最大挤压载荷几乎没有影响,而当μ>0.6时,可以明显降低最大载荷值,但也不是出口通道扩口直径越大其对应的挤压载荷就越小。试验研究表明,大型ECAP必须想办法降低摩擦才能实现批量化生产,试验和仿真的最大挤压载荷吻合。更多还原

【Abstract】 The finite element dynamic simulation using Deform-3D software and the experimental investigation of a large-scale equal channel angular pressing(ECAP) are carried out,with the special focus on the effect of both the friction coefficient between workpiece and ECAP die and the orifice size in exit channel of ECAP die on maximum pressing load.The finite element simulation results show that the shear friction model can be used in the finite element simulation of ECAP deformation.The friction coefficient between workpiece and ECAP die has very great effect on the maximum pressing load.With the increase of friction coefficient,the maximum pressing load increases considerably.As the friction coefficient varies from 0 to 0.6(approximately equal to the friction coefficient between aluminum and steel under dry friction condition),the maximum pressing load increases up to 5.1 times.The effect of the orifice size on maximum pressing load is found to be dependent on the magnitude of the friction coefficients.When the friction coefficients are smaller than 0.6,enlarging the orifice size has little effect on the maximum pressing load.On the other hand,when the friction coefficients are bigger than 0.6,the maximum pressing load can be obviously decreased with an enlarged orifice size,but the impact is not always improved with the increase of the orifice size.The experimental results demonstrate that the realization of ECAP scale-up and commercialization strongly depends on finding an approach to effectively reduce friction,and that the maximum pressing loads by the finite element simulation and the experiment are in accordance.更多还原