Pure Copper Sheets Processed by Constrained Studded Pressing: The Effect of Die Angle

The effect of the stud angle on the microstructure and mechanical properties of the pure copper sheets processed by constrained studded pressing (CSP) was investigated experimentally and numerically. The microstructure of the CSPed samples was studied using optical microscopy and transmission electron microscopy, and the dislocation density in the samples was determined using the Debye–Scherrer spectrum. The mechanical properties, including ultimate tensile strength, yield stress, elongation, and microhardness, were also measured. The results show that the first pass of the CSP caused the crystallite size in both die sets to decrease to nanometer sizes and the dislocation density in the samples increased significantly. The 60° dies induced a higher strain and a more severe dislocation accumulation and hence a more severe dynamic recovery in the Cu samples than the 30° dies, which caused the UTS of the samples obtained from the 60° dies to decrease more than that in the 30° dies after it reached to its maximum. It is shown that one pass of CSP with a 30° stud angle can achieve better ultimate tensile strength in pure copper sheets compared to the groove pressingf or constrained groove pressing methods.