A study on mechanical properties and microstructure of tetragonal zirconia-based composites

The relative density, bending strength, fracture toughness, and fracture surface microstructure of tetragonal zirconia (t-ZrO₂)-based composites prepared using magnetic pulsed compaction were investigated. The relative density and bending strength of the composites increased with increasing sintering temperature, whereas the fracture toughness increased with the addition of monoclinic zirconia (m-ZrO₂) and Al₂O₃ particles. Scanning electron microscopy images indicate that the m-ZrO₂ particles in the t-ZrO₂ matrix induce residual stress and micro-cracking. Al₂O₃ particles act as barriers to crack growth in t-ZrO₂/m-ZrO₂/Al₂O₃ composites.