Processing and Spark Plasma Sintering of zirconia/titanium cermets

This study focuses on the preparation of zirconia/titanium ceramic–metal composites. Three different metal contents (25 vol%, 50 vol% and 75 vol% Ti) have been selected from the entire range. First, to obtain stable and well-dispersed suspensions that will lead to optimum mechanical features, a rheology study has been performed by shifting two critical parameters: solid content and defloculant volume. Once the optimum conditions were selected, the powders obtained have been prepared to be sintered using Spark Plasma Sintering in order to reach the highest densities in the compacts. Microstructure and mechanical properties (bending strength, Vickers hardness and fracture toughness) of the different compositions have been studied, presenting in some cases values higher than expected by the rule of mixtures. X-ray diffraction studies have been performed throughout the work to optimise the parameters related to the sintering process, the system reactivity and mechanical response.