Sintering and Mechanical Properties of Mullite‐Reinforced Boron Carbide Matrix Composite

Abstract

In order to improve the mechanical properties of boron carbide (B 4 C) ceramic, a mullite‐reinforced B 4 C matrix ceramic with complete densification was fabricated via hot pressing for the first time. The dense sintering mechanism of mullite‐reinforced B 4 C ceramic was discussed through the phase and element analysis. A new dense sintering mechanism was found in which the diffusion of Si in mullite through the B 4 C matrix enhances the sintering of mullite‐reinforced B 4 C ceramics effectively. The mechanical properties and microstructure of the composite ceramics were investigated in contrast with monolithic B 4 C and one kind of commercial B 4 C ceramic. The flexural strength and fractural toughness of B 4 C with 3 vol% mullite addition reached 560 MPa and 3.33 MPa·m 1/2 , which is 154% and 96% higher than that of monolithic B 4 C, respectively.