Fracture toughness of pure copper sheet processed by constrained groove pressing (CGP)

Among severe plastic deformation methods, groove pressing is one of the prominent techniques for producing ultrafine grained sheet materials. This process consists of imposing repetitive severe plastic deformation on the plate or sheet metals through alternate pressing. In the current study, a 2mm pure Cu sheet has been subjected to repetitive shear deformation up to two passes. Fracture toughness tests have been performed and compared for three conditions of sheet material namely as received (initial annealed state), after one and two passes of groove pressing. Results of experiments indicate that a decrease in the values of fracture toughness have been attained as the number of constrained groove pressing (CGP) passes increased.