Deformation characteristics of zinc foam

Abstract

The temperature dependence of the yield stress and energy absorbing capacity of zinc foam, having a density between 0.05 and 0.07 of that of zinc, was determined over a range of temperatures from 0.1 T_m to 0.7 T_m approximately. With increase in temperature over this temperature range, the yield stress and energy absorbing capacity of the foam at first increased, and then subsequently decreased, above room temperature. At low temperatures,e.g. 0.1 T_m, the foam disintegrated into powder, and the energy absorbing efficiency parameters were high and independent of the foam density. In contrast, at the highest temperatures,e.g. 0.7 T_m, the energy absorbing efficiency parameters were lower and decreased with increase in density. The results are interpreted on the basis of the change in deformation mode which occurs in the zinc matrix of the foam over this temperature range,i.e. the transition from cleavage at the low temperature to plastic flow at the high temperature of deformation.