Toughening of (MgCoNiCuZn)O through addition of ZrO2(3Y) prepared by ultrafast high-temperature sintering

Abstract

To achieve low-cost preparation of high-performance high-entropy oxide, ZrO2(3Y)-reinforced (MgCoNiCuZn)O matrix composite ((MgCoNiCuZn)O–ZrO2(3Y)) was prepared in a few seconds by ultrafast high-temperature sintering (UHS) technology in this work. Microstructure, phase composition, crystal structure, and mechanical properties of the (MgCoNiCuZn)O–ZrO2(3Y) composite were investigated systematically. The results indicated that, after UHS sintering with applied current of 22 A for 2 min, the enhancement of ZrO2(3Y) were well dispersed in the (MgCoNiCuZn)O matrix. The microhardness and fracture toughness of the UHSed (MgCoNiCuZn)O–ZrO2(3Y) were 6.43 GPa and 2.27 MPa·m0.5, which were much higher than those of the traditional sintered (MgCoNiCuZn)O–ZrO2(3Y) (1.65 GPa and 0.98 MPa·m0.5) and UHSed (MgCoNiCuZn)O without ZrO2(3Y) (4.06 GPa and 1.42 MPa·m0.5). The toughening mechanism of the UHSed (MgCoNiCuZn)O–ZrO2(3Y) was discussed in detail based on the microstructural feature and crack propagation behavior. In summary, this study provided insight into the advantages of incorporating ZrO2(3Y) and UHS technology to reinforce high-entropy oxides.