Effect of ZrB2 on the microstructure, mechanical and tribological properties of Mo–Si–B matrix composites

Abstract

Composites with good mechanical and tribological properties are in high demand for engineering applications. Toward this aim, the Mo–12Si–8.5B alloy with 2.5–10 wt% ZrB2 ceramic was prepared. The effects of the ZrB2 content on the microstructure, mechanical properties, and tribological behavior were thoroughly investigated. The composites exhibited reduced density and enhanced hardness and strength owing to the dispersion strengthening of ZrB2 particles, thus resulting in improved wear resistance. The frictional properties are highly dependent on the ZrB2 content and counterpart materials. When coupled with GCr15 steel, it shows much slighter abrasive and adhesive wear; therefore, it presents a more preferable anti-wear performance. The wear rate of the composite with 7.5 wt% ZrB2 showed a minimum value of 2.71 × 10−7 mm3N−1m−1.