Comparative Study of HVOF-Sprayed NiCrBSi Alloy and 316L Stainless Steel Coatings on a Brass Substrate

Abstract

Brass alloys are used in many applications. However, improving their surface properties would help to increase their service life. For that, this study proposed to deposit using high velocity oxygen fuel (HVOF), nickel-chromium-boron-silicon (NiCrBSi) alloy, and 316L stainless steel (SS) coatings on brass substrates and investigate the mechanical properties and corrosion resistance of the coatings. The surface–interface morphologies, phases, and porosity of the coatings were analyzed using a scanning electron microscope and 3D profilometer. The adhesive strength and microhardness of the NiCrBSi and 316L SS coatings were also studied. Corrosion investigations were carried out using the salt fog test in an acetic acid salt spray atmosphere according to the NF EN ISO 9227 standard. This work showed that the 316L SS coatings presented a lower microhardness and higher adhesion strength than the NiCrBSi coatings despite their lower corrosion resistance. This could be explained by the microstructure of the coatings, the 316L SS coatings exhibiting more defects such as pores, un-melted particles, and oxides.