The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity...The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity is considerably decreased after the first pass, while subsequent passes result in better hardness behavior for the processed material. Also, the elongated grains formed in the first pass of the CGP are gradually converted to the equiaxed counterparts by adding pass numbers. Eventually, higher corrosion resistance of the sample by imposing the CGP process is related to the quick formation of passivation film and the change in the morphology of the second phase and precipitates which hinder their electrochemical reactions and decrease the potential localized attack sites.展开更多
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funded by“Quality Engineering Project of Anhui Province of China in 2016”entitled mold design and manufacturing experimental training center(2016sxzx050)。
文摘The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity is considerably decreased after the first pass, while subsequent passes result in better hardness behavior for the processed material. Also, the elongated grains formed in the first pass of the CGP are gradually converted to the equiaxed counterparts by adding pass numbers. Eventually, higher corrosion resistance of the sample by imposing the CGP process is related to the quick formation of passivation film and the change in the morphology of the second phase and precipitates which hinder their electrochemical reactions and decrease the potential localized attack sites.
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.
