THE STUDY OF ANTICORROSIVE COLD SPRAYED Al-Zn COATINGS FOR Nd-Fe-B PERMANENT MAGNETS

Abstract

Anticorrosive Al-Zn coatings applied on Nd-Fe-B permanent magnets were studied. The coatings were deposited on the surface of permanent magnets by high-speed cold spraying using various temperature conditions. The coatings were studied by optical metallography, scanning electron microscopy (SEM), quantitative X-ray diffraction analysis, and modern techniques for the estimation of adhesive strength of coatings. To determine the protective properties of Al-Zn coatings, salt spray corrosion tests were performed. The properties of the cold sprayed Al-Zn coatings are found to depend on the temperature of spraying. The coatings prepared at a spraying temperature of 200 °С exhibit the best results. The increase in the deposition temperature above 200 °С leads to the increase in the content of large corundum particles in the coatings, which result in the embrittlement of the coating material.