Novel method of powder-based processing of copper nanofoams for their potential use in energy applications

This paper discusses a new method of powder-metallurgy processing to produce regular-structured Cu nanofoams or irregular-structured Cu foams containing both micropores and nanopores. Coarser Cu nanofoam struts (approximately 2.5 times larger) formed in the ribbon samples of the foams subjected to additional sintering at 900 C after initial lower-temperature sintering at 450 C than those formed in the ribbon samples of the foams subjected to additional sintering at 700 C. Furthermore, a much higher degree of strut continuity was observed in the Cu nanofoam sintered at 900 C, which should improve the ductility and structural integrity of the Cu nanofoam. This study can be considered as a framework for using a simple method of powder-based dealloying to produce nanoporous and micro/nanoporous metallic foams for a variety of energy-based applications requiring metallic foam materials with a high density of specific surface area. Although the dealloying process of achieving Cu nanofoams is not new, this powder-based method has significant implications because often a difficult and expensive material shaping process can be avoided by forming the precursor alloy with a near-net shape geometry in the method.