A two dimensional computational study of a gasar porous copper microstructure

The ‘gasar’ process uses a metal—hydrogen eutectic reaction to produce varied pore morphologies in metals such as copper, magnesium, nickel and aluminum. Experimental observations and unit cell studies of pore deformation interactions in copper ‘gasar’ materials suggest that the pore microstructure geometry will induce multiaxial states of deformation that contribute to the retention of significant bulk material strength. In this investigation, a two dimensional finite element study of the pore interactions in a 21.5% porosity gasar copper was performed. The finite element model was based upon a micrograph of the actual porosity microstructure. The pore microstructure in this material features a range of elongated pores, averaging 18 μm in diameter and 108 μm in length and accounting for 18% of the total porosity. Different in-plane and out-of-plane constraint combinations were studied. The results of these simulations show the development of very nonuniform mesoscale stress and strain patterns across the microstructure. These patterns are produced as a consequence of pore shape, pore spacing, pore free zones and spatial offsets. The results support the conclusions of earlier unit cell studies on the role that these features play in bulk properties.