Improvement of Corrosion and Wear Resistance of CoCrNiSi[sub.0.3] Medium-Entropy Alloy by Sputtering CrN Film

In this study, Co, Cr, and Ni were selected as the equal-atomic medium entropy alloy (MEA) systems, and Si was added to form CoCrNiSi[sub.0.3] MEA. In order to further improve its wear and corrosion properties, CrN film was sputtered on the surface. In addition, to enhance the adhesion between the soft CoCrNiSi[sub.0.3] substrate and the super-hard CrN film, a Cr buffer layer was pre-sputtered on the CoCrNiSi[sub.0.3] substrate. The experimental results show that the CrN film exhibits a columnar grain structure, and the film growth rate is about 2.022 μm/h. With the increase of sputtering time, the increase in CrN film thickness, and the refinement of columnar grains, the wear and corrosion resistance improves. Among all CoCrNiSi[sub.0.3] MEAs without and with CrN films prepared in this study, the CoCrNiSi[sub.0.3] MEA with 3 h-sputtered CrN film has the lowest wear rate of 2.249 × 10[sup.−5] mm[sup.3]·m[sup.−1]·N[sup.−1], and the best corrosion resistance of I[sub.corr] 19.37 μA·cm[sup.-2] and R[sub.p] 705.85 Ω·cm[sup.2].