关键词: 大型化, 等通道转角压, 最大挤压载荷

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.

Key words: Equal channel angular pressing, Maximum pressing load, Scale up