High Temperature Deformation Behaviors and Constructive Relation of the Porous Cu-Ni-Al Sintered Alloys

Abstract

The Cu-Ni-Al powders are prepared by atomization method, are hot pressing sintered in the vacuum furnace to prepare the porous Cu-Ni-Al alloy. The microstructure, high-temperature compressive deformation behavior and its effect factors are investigated,respectively. The deformation mechanism of the porous Cu alloy is also analyzed and discussed. The results show that the compression strength, elastic modulus and yield strength decrease with increasing temperature and decreasing strain rate. The compression deformation process is classified in terms of three stages of linear elastic deformation, yield platform area with pore wall buckling, collapse, and plastic deformation with pore densification. In the high temperature compression deformation process, stress concentration and deformation are preferred to occur at the areas with pore concentration and thinner pore walls. The compressive mechanical model of the porous Cu alloy is established using the method of linear regression. It is obvious that the calculation curves is in accordance with the experimental curves in the first and second stages of the deformation process, however, at the third stage,the former is above the experimental curves, which is possibly attributed to the inhomogeneous pore distribution of the porous Cu alloy.