Investigating the Sintering Behavior of Porous Composites Made from Metallic Ni and YSZ Powders

The aim of this investigation is to characterize the influence Ni oxidation has on the sintering of tape‐cast Ni/YSZ composites made from coarse and fine nickel metal powders compared with preoxidized NiO/YSZ mixtures. During heating to 900°C, the NiO/YSZ composites shrink while the coarse Ni/YSZ composites expand, due to nickel oxidation. Fine Ni/YSZ powders do not exhibit oxidation‐induced expansion. Most densification occurs during high‐temperature sintering to 1475°C, the Ni/YSZ composites shrinking less than the NiO/YSZ composites. Analysis indicates that swelling due to Ni oxidation dominates the volumetric changes at low Ni contents, while sintering dominates at high Ni volumes.