Abstract
In this study, the effect of sintering temperature on the phase composition, density, microstructure, and mechanical properties of multidoped zirconia-toughened alumina (MZTA) ceramics containing multidoped zirconia (Zr0.90(Y, Ce, Ca, Mg)0.10O2) was investigated. The samples were fabricated using a conventional ceramic processing and sintered at temperatures ranging from 1400 to 1600 °C for 5 h. X-ray diffraction and whole-powder-pattern fitting (WPPF) analysis showed that, regardless of the sintering temperature, the samples consisted predominantly of t-ZrO2 and Al2O3 phases, with a minor (0.7–2.8 wt. %) amount of m-ZrO2 detected at certain temperatures. Scanning electron microscopy revealed that increasing the sintering temperature from 1400 to 1600 °C resulted in an increase in the average Al2O3 grain size from 0.39 to 1.32 µm and the ZrO2 grain size from 0.28 to 0.92 µm. The sample sintered at 1500 °C exhibited the best combination of microhardness (HV5 1748) and flexural strength (620 MPa), owing to its high density and homogeneous microstructure. At higher sintering temperatures, abnormal grain growth accompanied by a decrease in density was observed, resulting in a reduction in flexural strength. The fracture toughness (KIC) showed an approximately linear increase with increasing sintering temperature.