摩擦阻力对纯铝在等径弯角挤压过程中变形的影响

室温下对纯铝试样进行了等径弯角挤压(ECAE)，通过对挤压后纯铝试样的宏观变形及微观形貌分析，探讨了ECAE过程中模具内壁与试样之间的摩擦阻力对试样变形的影响，得到了滞变区比例与挤压位移之间的关系．结果表明：挤压过程中试样在模具通道内角点附近形成难变形区；在模具通道外角点形成变形死区；试样的芯部变形比较均匀，为明显的剪切变形；受摩擦阻力的影响，试样顶部和底部均出现了滞变区，该区域呈轴对称分布且沿试样长度方向逐渐向试样芯部扩展；滞变区比例随挤压的进行而增大．

Influence of Friction Resistance on the Deformation of Pure Aluminum during Equal Channel Angular Extrusion Processing

Pure aluminum was subjected to equal channel angular extrusion(ECAE) at room temperature. Based on the analysis of macrostructure and microstructure of the sample after ECAE, the influence of friction resistance between the die wall and the sample on the deformation of the sample billet was discussed. A relationship between the less-sheared region percentage and extrusion displacement was established. The results show that a difficult-sheared region exists in the vicinity of the inner corner of the die channel; a dead zone at the outer corner of the die channel and obvious uniform shear deformation at the middle region of sample during ECAE processing are formed. The less-sheared regions caused by friction resistance are observed at lower and top parts, which are symmetric and gradually extend to the inner part along the sample longness. The less-sheared region percentage increases with ECAE processing.