A mesoscale computer simulation of multiaxial yield in gasar porous copper

The mesoscale biaxial plastic flow of a porous copper material produced by the 'gasar' gas-eutectic solidification process is examined in this study. The pore morphology is characterized by elongated, oriented and partially ordered pores. Tensile and compressive testing suggested a very anisotropic yield response, weak coupling between stresses generated by deformations applied in the directions parallel to and transverse to the longitudinal pore axes, and bulk density decreases associated with compression in the longitudinal direction. A two dimensional explicit finite element model, based on an image of the microstructure, was subjected to combinations of tensile, zero and compressive displacement loads applied to the model boundaries. The simulations provided insight into the evolution of local micro yielding, plastic connectivity across the microstructures and buckling of the pores to explain the experimental observations. (C) 1998 Elsevier Science S.A. All rights reserved.