Deformation and fracture behaviour of porous FVS0812 aluminium alloy prepared by spray deposition

Abstract

The deformation and fracture behaviour of a porous FVS0812 aluminium alloy prepared by spray deposition was investigated using compression testing. Rapid densification of the porous alloy was observed before a height reduction of ~50%. The optimum strain rate and deformation temperature to achieve maximum density were determined. Microstructural evolution involved the following stages: breakup of boundaries between adjacent particles; plastic deformation of particles; and collapse of large pores into various smaller pores and their disappearance. A strain hardening phenomenon occurred at all strains when compression was carried out at at 573 and 673 K, while a recovery mechanism came into operation at 773 K and a true strain of 0.2. The critical strain for the occurrence of strain softening in the porous alloy was much higher than that for the fully dense alloy. The fracture criteria curve of the porous alloy was a straight line, with a slope of ~0.45268 at high temperature and ~0.47636 at room temperature, almost parallel to that of the fully dense alloy in homogeneous compression.