Microstructure And Functional Properties Of Prosthetic Cobalt Alloys CoCrW

Abstract

The material subject to investigation was two commercial alloys of cobalt CoCrW (No. 27 and 28) used in prosthodontics. The scope of research included performing an analysis of microstructure and functional properties (microhardness, wear resistance and corrosion resistance), as well as dilatometric tests. The examined alloys were characterized by diverse properties, which was considerably influenced by the morphology of precipitates in these materials. Alloy No. 27 has a higher corrosion resistance, whereas alloy No. 28 shows higher microhardness, better wear resistance and higher coefficient of linear expansion. Lower value of the expansion coefficient indicates less probability of initiation of a crack in the facing ceramic material.

Anticorrosion Protection of New Composite Coating for Cobalt-Based Alloy in Hydrochloric Acid Solution Obtained by Electrodeposition Methods

“…These proceedings were related in prior works [10,40,51]. The insoluble constituents achieved via the passivation process are complexes of cobalt oxides and cobalt salicylates that impede the metal from dissolving without complicating the electrochemical polymerization technique [51,[53][54][55][56]. By developing polymerization parameters, we were able to achieve composite films of P3MPY-SDS/P2MT that have a significant protective impact.…”

“…Analyzing Figures 5-7 and Tables 1-3, it is indicated that the lowest corrosion speed and the highest protection performance were obtained by the P3MPY-SDS/P2MT composite at 0.9 V and 1.0 V, at current densities of 0.5 mA/cm 2 and 1 mA/cm 2 (at a 5:1 molar ratio, t = 20 min) at current density (at 5:1 and 1:5 molar ratios), and a very good defense was achieved at 1.0 V and 1 mA/cm 2 (at a 1:5 molar ratio, t = 10 min) versus the uncoated substrate in a 1 M HCl environment. The corrosion processes of the composite-coated cobalt alloy and the bare sample in the HCl medium can be effectuated as follows [5,[23][24][25][26][27]35,[52][53][54][55][56][57][58]:…”

“…M. Behazin et al studied the influences of γ-radiation on the corrosion of a Co alloy at pH values of 6.0, 8.4, and 10.6, and the results of this study indicate that γ-irradiation raises the oxidation rate of Co, but this effect intensifies with changes in pH. Irina Smolina et al explored the wear and corrosion resistance of laser surface alloyed (LSA) cobalt alloy rhenium by utilizing an LDF diode laser (4000 W) [51][52][53][54][55][56][57].…”

“…Co alloys are frequently utilized in the automotive industry in various components, in nuclear reactors, and in different areas of the petrochemical, energy, and food industries. Cobalt alloys with different alloying elements to improve their properties are also used in the aerospace industry, in medical equipment, as particular metallic biomaterials, and as finishings for industrial instruments for woodworking [52][53][54][55][56][57]. The corrosion and wear of Co alloy were explored in highly acidic and basic environments, in chlorinated and saline media, in a sulfuric acid medium, and in slightly alkali media (at a pH of 10); though the outcomes of these tests are difficult to explore, and general corrosion parameters were complicated to obtain.…”

“…Protective action on a Co alloy is especially important and has been considered by a great number of researchers. At present, research on the operation of inhibitors on Co substrates and their protection process has been completely intensified, and exciting developments have been made in corrosion control [51][52][53][54][55][56][57]. Tengda Ma et al investigated the protection efficiency of disulfide derivatives against Co alloy corrosion in an alkaline environment; the corrosion protection performance of DDA and DPD reached up to 90%.…”