Corrosion Studies on Nickel-Based Casting Alloys

Publisher Website
Google Scholar
Abstract
Three different methods—electrochemical measurements (polarization curves, polarization resistance curves, and open-circuit potentials), immersion tests, and in-vivo evaluation—have been used to investigate the corrosion resistance of commercial nickel-chromium dental casting alloys and of the newly developed nickel-vanadium and nickel-vanadium-chromium alloys.Nickel-chromium alloys can be assigned to five different classes, according to their composition. All of the three methods of investigation used in this study have demonstrated that the electrochemical behavior of these alloys differs markedly among classes, and even within a given class. The molybdenum and manganese contents do play a significant role in corrosion resistance: alloys with high molybdenum and manganese content exhibit a much wider passivation range and a better resistance to pitting in chloride-containing solutions than those without. Alloys without any molybdenum are constantly active and corroding. The addition of cobalt or gallium as a ternary constituent also enhances corrosion resistance.The nickel-vanadium-chromium system offers good promise for the development of a new type of alloy for possible use in dentistry. The alloy 57Ni-25V-18Cr, for example, compares favorably with existing nickel-chromium alloys and even outclasses them for yield strength and polarization resistance.A thorough evaluation of the biocompatibility of all nickel-based alloys, according to the newest recommended practices, is still needed.
Keywords

This publication has 6 references indexed in Scilit: