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.