Microwave sintering of a ZrB2-B4C particulate ceramic composite

A two phase particulate ceramic composite containing ZrB2 and B4C was densified by microwave sintering a mixture of ZrB2 and 4 wt% B4C powders. The particulate composite reached >98% relative density at processing temperatures as low as 1720 °C. In comparison to conventional sintering, microwave sintering promoted densification of the composite at lower temperatures without promoting rapid grain growth. Vickers' hardness and fracture toughness of the microwave sintered specimens were as high as 17.5 GPa and 3.8 MPa m1/2, respectively.