Microstructure and mechanical properties of Al 2 O 3 /ZrO 2 composites by two‐step sintering

Composites of Al 2 O 3 /ZrO 2 (containing 25, 50, and 75 vol% ZrO 2 ) were prepared by mixing Al 2 O 3 and ZrO 2 suspensions. The microstructural control via two‐step sintering (TSS) was the main objective of this work. For this purpose, different sintering curves were constructed, aiming to achieve the best temperature combination for the sintering steps that provides higher density and finer microstructure. The results were compared with single‐step sintering (SSS). Furthermore, microhardness and fracture toughness were measured for the best TSS specimens under each composition. The results showed that the high densities were obtained, and the reduction of grain size was greater than 40% for two‐step sintered specimens, compared to SSS ones. Consequently, microhardness values increased. However, fracture toughness values remained unchanged.