Tribological behavior of B4C reinforced Fe-base bulk metallic glass composite coating

In the present study, the tribological behavior of B₄C reinforced Fe-based bulk metallic glass (BMG) in the form of spray coatings was investigated. These coatings were successfully deposited on mild steel substrates using shrouded plasma spray techniques. The B₄C fraction and distribution in the deposited BMG/B₄C coatings were evaluated by image analysis and scanning electron microscopy. Friction and wear experiments were performed under dry conditions using a pin-on-disk sliding wear test against SUJ2 countermaterial for different B₄C fractions. It was observed that the wear resistance of composite coatings was greatly improved relative to the BMG coating. The results show that the friction coefficient of BMG/B₄C coatings is dependent on the fraction of B₄C in the BMG matrix. The wear behavior of Fe-based BMG is governed by plastic deformation and fracture of the wear surface. By embedding a harder material, B₄C, in a comparatively soft matrix, the hardness of the wear surface can be increased, and plastic flow propagation is inhibited. Moreover, the lower friction coefficient of B₄C can lead to reductions in wear loss.