Microstructural Evolution and Thermal Stability of Pure Copper Processed by Severe Plastic Deformation

Document Type : Original Article


School of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.


Annealed pure copper samples of 99.97 wt. % processed at room temperature by Equal Channel Angular Pressing (ECAP) technique with route Bc up to 8 passes followed by cold rolling up to 75% reduction in thickness. The sample was followed by isothermal annealing at different temperatures. The recrystallized microstructure was detected by using EBSD technique. Isochronal and isothermal annealing was performed to investigate the material’s behavior by measuring the change of Vickers microhardness. With increasing annealing temperature, the microstructure becomes more homogeneous while the microhardness decreases dramatically. A modified standard JMAK- microhardness Model used to analyze the Kinetics of recrystallization of the annealed deformed samples, in this approach the JMAK model expressed in terms of microhardness measurements. JMAK exponent, n, the temperature dependent constant, k, and the activation energy, Q, for recrystallization are obtained.