Hierarchically Structured, Highly Porous Nickel Synthesized in Sintering–Evaporation Process from a Metal Nanopowder and a Space Holder

Abstract

Permeable (~70% porosity) nickel with a pronounced hierarchical structure was synthesized by powder metallurgy methods in sintering–evaporation process from a nickel nanopowder and an ammonium bicarbonate micropowder as a space holder. The obtained porous nickel contained pores of three spatial scales: macropores (30–50 μm in size), their connecting windows (5–10 μm), and interparticle micropores (less than 1 μm) in the walls of macropores. The produced material is characterized by a network of interpenetrating macropores and by a developed surface of their walls consisting of several layers of sintered nickel nanoparticles.