Synergistic strengthening and toughening of oscillatory pressure sintered WC-ZrO2-Al2O3 ceramics

WC-ZrO2-Al2O3 ceramics with high performance were prepared by oscillatory pressure sintering, and their densification behavior, microstructure and mechanical properties were investigated. The results showed that addition of ZrO2-Al2O3 composite powder can reduce the sintering temperature (from 1900 ? to 1760 ?) and promote densification of the ceramics. When the ZrO2-Al2O3 composite powder content was 8 wt%, it exhibited the best mechanical properties including Vickers hardness of 24.95 GPa, fracture toughness of 7.74 MPamiddotm(1/2) and flexural strength of 1329 MPa. The main strengthening and toughening mechanisms included the phase transformation of zirconia, crack deflection, crack bridging and the presence of many dislocation defects. Also, the formation of well-matched coherent interfaces of WC/ZrO2 and WC/Al2O3 contributed to a synergistic improvement in strength and toughness of WC-ZrO2-Al2O3 ceramics. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The study found that addition of ZrO2-Al2O3 composite powder can reduce the sintering temperature and promote densification of WC-ZrO2-Al2O3 ceramics, with the ceramics exhibiting the best mechanical properties at 8 wt% of ZrO2-Al2O3 composite powder content.