Chemical composition and microstructure of Al3BC3 prepared by different densification methods

“Al8B4C7” and Al3BC3 powders were synthesized, and the formation of secondary phases was suppressed during the densification of the ternary aluminum borocarbides. The so-called “Al8B4C7” was Al3BC3 containing excess Al and B. The excess components in “Al8B4C7” promoted the densification of Al3BC3. The formation of secondary phases could not be controlled when using the reactive hot pressing method during the densification of Al3BC3. In contrast, monolithic Al3BC3 was obtained by separating calcination and hot pressing stage. The hardness, Young's modulus and fracture toughness of the sintered Al3BC3 were 13.9 GPa, 136 GPa and 2.2 MPa m1/2, respectively.