Sintering behavior and thermal expansion of zirconia\u2013titanium composites

Abstract

The dilatometric and thermogravimetric methods were used to investigate the sintering conditions of 3Y–ZrO2 and 3Y–ZrO2–Ti composites. For the materials preparation, the nanometric zirconia stabilized by 3 mol% Y2O3 powder and micrometric titanium powder (3 and 10 vol%) were used. The green body samples were formed by slip casting method. The morphology of samples microstructures was determined by SEM observations. The stereological analysis of zirconia and zirconia–titanium composites was carried out using computer program. The density was measured using the Archimedes method. The hardness of sinters was also investigated. Addition of Ti into ZrO2 influenced the sintering behavior and thermal expansion of obtained composites. The analysis of the sintering process and characteristic temperatures confirmed the increase of onset and final temperature of shrinkage with the increase in Ti content. The changes of the thermal expansion curves for the pure zirconia and 3Y–ZrO2–Ti composites were the result of the αTi → βTi transformation and the transition temperature of the zirconia m → t transformation. The zirconia and composite samples were characterized by relative density about 98%, close to theoretical density. The slight growth of zirconia grains was observed.