Abstract:Reticulated open-cell Ni-Cr-Fe foams were manufactured by gas-phase codeposition of Cr and Fe onto the struts of pure Ni foam at 1050 °C, and then the samples were homogenization treated at 1200 °C in a vacuum atmosphere. The quasi-static compressive behavior and energy absorption characteristics of the Ni-Cr-Fe alloy foams with different Cr and Fe contents were discussed. The mechanical properties of these open-cell Ni-Cr-Fe alloy foams were also comparable with the pure Ni foams or the hypothetical Ni-Cr-Fe foam model. The results show that although the alloy foam struts show the similar hardness, the compressive strengths and energy absorption properties of the open-cell Ni-Cr-Fe alloy foams increase with increasing the Cr and Fe contents. The stress-strain behaviours of the Ni-Cr-Fe alloy foams are as smooth as those of nickel foams, indicating that the Ni-Cr-Fe alloy foams are the characteristic of typical ductile metallic foam. The energy absorption capabilities of the Ni-Cr-Fe alloy foams exhibit 22 times higher than that of the pure Ni foams. Simultaneously, the compressive strength of the Ni-Cr-Fe alloy foams at ambient temperature is in agreement with theoretical prediction by Gibson-Ashby model.

Key words: metallic foam; Ni foam; vapour deposition; coating; heat treatment; pack cementation