Constrained groove pressing（CGP） is a new severe plastic deformation method suitable for producing ultra-fine grained sheet metals. In this work, the processing efficiency for a muti-pass CGP of pure copper was inve...Constrained groove pressing（CGP） is a new severe plastic deformation method suitable for producing ultra-fine grained sheet metals. In this work, the processing efficiency for a muti-pass CGP of pure copper was investigated. With a relatively small groove width of 2 mm and tight constraint, a sharp variation of mechanical properties with pass number is observed. Subgrains with the size of＊0.5 lm have distinct boundaries, which is the predominant feature in the microstructure after three passes. The evolution of deformation homogeneity characterized by micro-hardness distribution was examined in detail.Observations of optical micrographs and fracture surface morphology confirm the evolution rule. The relation between electrical resistivity and accumulative plastic strain was discussed. Crystalline defects, micro-cracks, and microstructure uniformity together determine the change of electrical resistivity of CGP copper.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51375269)Program for New Century Excellent Talents in University (No.NCET-080337)Graduate Independent Innovation Foundation of Shandong University (No. yzc12122)
文摘Constrained groove pressing（CGP） is a new severe plastic deformation method suitable for producing ultra-fine grained sheet metals. In this work, the processing efficiency for a muti-pass CGP of pure copper was investigated. With a relatively small groove width of 2 mm and tight constraint, a sharp variation of mechanical properties with pass number is observed. Subgrains with the size of＊0.5 lm have distinct boundaries, which is the predominant feature in the microstructure after three passes. The evolution of deformation homogeneity characterized by micro-hardness distribution was examined in detail.Observations of optical micrographs and fracture surface morphology confirm the evolution rule. The relation between electrical resistivity and accumulative plastic strain was discussed. Crystalline defects, micro-cracks, and microstructure uniformity together determine the change of electrical resistivity of CGP copper.
