Fabrication and mechanical behavior of porous Cu via chemical de-alloying of Cu25Fe75 alloys

Abstract

We report on a study of the synthesis and deformation of bulk porous Cu processed via plasma activated sintering (PAS) of Cu-Fe precursor alloys. The process used in our work involved both low temperature (600–900 °C) and low pressure (50 MPa) followed by chemical de-alloying of Cu-Fe in a solution of 5 wt% H2SO4. Our results show that when this approach is applied to a Cu-75 at.% Fe alloy, de-alloying of the active Fe phase leads to the formation of micron-sized 1–4 μm pores and approximately 73 vol% porosity. Our results show that the microstructure of the porous Cu principally depends on the morphology of the precursor Cu25Fe75. Moreover, studies of the relationship between the microstructure and compressive deformation behavior of porous Cu reveal that the mechanical strength increases with decreasing pore size in the linear elastic and plateau regions, but decreases with decreasing pore size in the densification region. The stress level corresponding to the plateau stage in the range of 16.11–18.11 MPa corresponding to a strain of 30%.