摩擦系数对不同截面纯锆单道次ECAP变形影响的有限元模拟与实验验证

利用商业有限元软件Abaqus模拟不同截面形状纯锆试样在不同摩擦系数条件下单道次等通道转角挤压变形。模拟结果表明,摩擦系数对挤压载荷有明显影响,随着摩擦系数的增大,截面形状对挤压载荷的影响越来越小。同时发现,随着摩擦系数的增大,Z面等效应变分布均呈减小趋势,且圆形试样减小幅度大于方形试样,说明摩擦及圆形截面有助于工业纯锆的均匀变形;对X面的等效应变分布分析发现,摩擦系数对圆形试样X面等效应变分布影响不大,方形试样X面变形均匀性随摩擦系数的增大而减小。考虑到摩擦会导致挤压力过大,因此在挤压过程中应适当减小摩擦系数,并选择圆形截面试样。

Finite Element Simulation and Experimental Vertification for the Influence of Friction Coefficient on One-pass ECAP of Commercially Pure Zr with Different Cross Sections

Single pass ECAP deformation of commercially pure zirconium (CPZr) with different cross section in various friction coefficients conditions was simulated using the Abaqus commercial software. The results show that the friction coefficient has significant effect on extrusion loading. With the friction coefficient increasing, the influence of the cross section shape on the extrusion loading decreases dramatically and the equivalent strain distribution of longitudinal section tends to decrease. Furthermore, the circular specimen decreases more severely than the square specimen, which indicates that high friction coefficient and circular specimen are helpful to the homogeneous deformation. The friction coefficient has no obvious influence on the equivalent strain distribution on cross section of the circular specimen. While the equivalent strain homogeneity on cross section of the square specimen decreases with the friction coefficient increasing. Because high friction coefficient can make extrusion loading increase, low friction coefficient and a circular specimen should be used in ECAP experiment.