Distributions of hardness and strain during compression in pure aluminum processed with equal-channel angular pressing and subsequent annealing

Single compression tests were conducted for two types of pure Al (99.99%): one processed using equal-channel angular pressing (ECAP) through route Bc for 8 passes and the other with the same ECAP but successively annealed at 573 K for 1 h. The distributions of the equivalent strain introduced by the compression were quantitatively examined by finite element analysis (FEA). Comparison was made between the ECAP samples and the ECAP-annealed samples with regard to the inhomogeneity and magnitude of the strain developed during the compression. Hardness variations with the equivalent strain were also compared with those obtained by earlier studies using ECAP and high-pressure torsion. Moreover, the hardness variation throughout the cross section after compression was well predicted using the FEA for both ECAP sample and ECAP-annealed sample. It is shown that the change in the strain path from ECAP to compression affects the hardness variation with respect to the equivalent strain.