Compressive behavior of aluminium foams prepared by powder metallurgy method

摘要

The compression behavior of closed cell aluminum foams with different density has been examined. Stress-strain curves were obtained. The microstructure evaluation of cell walls was investigated using X-ray computer tomography. A series of images of internal microstructures were given, the structural deformation evolution was analyzed. The images of cell wall evolution shown that crack appeared in cell wall after a small deformation of elastic deformation. As the compression proceeded, further cracks occur and some of the cell walls fracture. The fracture area become expanded, a part of dislocation on the sample side is formed. As the fracture area spreads, some regions become dense. The stress-strain curves showed brittle characteristics. As the relative density increases, yield strength and elastic modulus of aluminum foams increased. The best fit lines are obtained, where, ψ is 0.97 and 0.2 respectively.