Effect of Shape of Pore Forming Agent on Structure and Properties of Aluminum Foams

Abstract

The aluminum foams was prepared by powder sintering method. Internal pores were made of spherical urea particles or bar-shaped urea particles, and the influence of this factor was studied. The internal structure and composition of the aluminum foams were measured by SEM and XRD, then the effects of the shape of pore forming agent on the porosity, compressive property and energy absorption efficiency were researched. Finally, the micro-residual stress in the aluminum foams was calculated. The results show: the porosity of the aluminum foams is slightly lower than the volume fraction of urea particles after the sintering process; the maximum micro-residual stress of aluminum foams with spherical urea particles is 47.22 MPa and the maximum micro-residual stress of aluminum foams with bar-shaped urea particles is 57.38 MPa; the aluminum foams with spherical urea particles is more stable than the others, the compressive strength of the aluminum foams with spherical urea particles is also stronger; when entering the platform area, the energy absorption efficiency of aluminum foams with spherical urea particles is obviously higher, and its maximum efficiency of energy absorption is 71.9%.