Effect of surface microstructure for corrosion resistance and magnetic properties of an amorphous cobalt-based Co-Si-Fe-Cr-Al ALLOY

Abstract

The surface of an amorphous cobalt-based alloy of nominal composition Co75Si15Fe5Cr4.5Al0.5 was modified by nanostructures at anodizing in an ionic liquid – bis(trifluoromethane sulfonyl)imide 1-butyl-3-methyl- imidazolium. The magnetic (saturation specific magnetization and coercive force) and corrosion (corrosion potential and resistance) characteristics of an amorphous alloy before and after electrochemical modification of the surface by nanostructures are compared. Modification of the alloy surface partially changes its magnetic properties. After corrosion tests, an increase in the value of coercive force is observed. Corrosion tests were carried out by the method of polarization curves in Ringer’s solution. The corrosion resistance of alloys modified by oxide nanostructures is higher than the corrosion resistance of a polished alloy. The increase in corrosion resistance is mainly determined by the presence of nanostructures.