Microstructure and mechanical properties of microwave sintered (MgCoNiCuZn)O high-entropy ceramics

The microstructure, reaction mechanism and mechanical properties of (MgCoNiCuZn)O high-entropy ceramics prepared by microwave sintering technology were studied. Single -phase (MgCoNiCuZn)O high-entropy ceramics can be prepared in about 1 h when the preforming pressure is 5 MPa and the temperature is higher than 900 degrees C. By analyzing the microscopic morphology and density, it can be known that the density gradually increases with the increase of temperature. When the temperature is higher than 1000 degrees C, the pores in the sample indicate the packing, agglomeration and segregation of Cu2+ atoms at the grain boundaries. When the mass of the raw material is 20 g, it exhibits a good impedance matching effect during microwave heating. The sintered (MgCoNiCuZn)O ceramic with a density of 92.87 %, a flexural strength of 290 +/- 20 MPa, an elastic modulus of 187.05 +/- 5 GPa, and a microhardness of about 7 GPa.