中文摘要：

分别沿与冷轧Cu板轧向成0°（RD-0°）,45°（RD-45°）和90°（RD-90°）方向取帽形试样,利用Split-Hopkinson压杆实验装置,研究了强迫剪切条件下冷轧Cu板的动态变形特征.结果表明：冷轧Cu板强迫剪切动态力学行为呈现出明显的各向异性,RD-90°方向屈服强度和峰值应力最大,RD-45°其次,RD-0°方向最小.不同方向的绝热剪切变形行为也表现出较大的差异,RD-0°方向的绝热剪切带内的变形相比其它2个方向均匀,绝热剪切敏感性最弱.基于剪切应力-剪切应变曲线和绝热剪切扩展所需能量,定性解释了不同方向绝热剪切敏感性的差异.EBSD的实验观察表明,3个方向上的剪切带内均有超细晶存在.基于亚晶旋转动态再结晶机制,理论计算结果证实了剪切带内发生再结晶的动力学可行性.

英文摘要：

The dynamic forced shear deformation behaviors of cold-rolled Cu sheet were investigated by means of Split-Hopkinson pressure bar technology.Hat-shaped specimens of cold-rolled Cu sheet,which were cut with the axes along the 0°（RD-0°）,45°（RD-45°） and 90°（RD-90°） directions from rolling direction lying in the rolling plane,were compressed with shear strain rate of 3.5×l0~4 s~（-1）. The results show that the forced shear behaviors of cold-rolled Cu sheet for different directions exhibit pronounced anisotropy,both the yield strength and flow stress for the RD-90°direction sample are the maximum while those for the RD-0°direction are the minimum.The adiabatic shear deformation characteristics for different direction samples display much distinction.The adiabatic shear susceptibility of RD-90°sample is the strongest while the RD-0°is the weakest.Based on the shear stress-shear strain curves and adiabatic shear dissipation energy,the difference of adiabatic shear susceptibility for different directions can be explained qualitatively.The ultrafine grains can be found within the shear bands for three different directions by electron backscatter diffraction（EBSD）.The calculated results prove the possibility that the dynamic recrystallization can happen in shear bands based on the rotational dynamic recrystallization mechanism.