Effect of CeO ₂ and Al ₂ O ₃ contents on Ce‐ZrO ₂ /Al ₂ O ₃ composites

Abstract

Abstract Effect of CeO 2 and Al 2 O 3 contents on phase composition, microstructures, and mechanical properties of Ce–ZrO 2 /Al 2 O 3 composites was studied. The CeO 2 content in CeO 2 –ZrO 2 varied from 7 to 16 mol%, and the Al 2 O 3 content in Ce‐ZrO 2 /Al 2 O 3 composites were 7 and 22 wt%. When CeO 2 content was ≤10 mol%, high Al 2 O 3 content contributed to hinder the tetragonal‐to‐monoclinic ZrO 2 phase transformation during cooling and decrease the density of microcracks in the composites. Tetragonal ZrO 2 single‐phase was obtained in the composites with ≥12 mol% CeO 2 , regardless of the Al 2 O 3 content. Hardness, flexural strength, and toughness were dependent on CeO 2 and Al 2 O 3 contents which were related to the microcracks, grain size, and phase transformation. The high flexural strength and toughness of the composites with 7wt% Al 2 O 3 could be obtained at an optimum CeO 2 content of 12 mol%, whereas those of the composites with 22 wt% Al 2 O 3 could be achieved in the wide CeO 2 content range of 8.5‐12 mol%.