On the Prospects of Using Nanoindentation and Wear Test to Study the Mechanical Behavior of Fe-Based Metallic Glass Coating Reinforced by B4C Nanoparticles

Abstract

In this study, Fe-based metallic glass was served as the matrix in which various ratios of hard B4C nanoparticles as reinforcing agents were prepared using a high-energy mechanical milling. The feedstock nanocomposite powders were transferred to the coatings using a high-velocity oxygen fuel process. The results showed that the microstructure of the nanocomposite coating was divided into two regions, namely a full amorphous phase region and homogeneous dispersion of B4C nanoparticles with a scale of 10 to 50 nm in a residual amorphous matrix. As the B4C content is increased, the hardness of the composite coatings is increased too, but the fracture toughness begins to be decreased at the B4C content higher than 20 vol pct. The optimal mechanical properties are obtained with 15 vol pct B4C due to the suitable content and uniform distribution of nanoparticles. The addition of 15 vol pct B4C to the Fe-based metallic glass matrix reduced the friction coefficient from 0.49 to 0.28. The average specific wear rate of the nanocomposite coating (0.48 × 10−5 mm3 Nm−1) was much less than that for the single-phase amorphous coating (1.23 × 10−5 mm3Nm−1). Consequently, the changes in wear resistance between both coatings were attributed to the changes in the brittle to ductile transition by adding B4C reinforcing nanoparticles.