Sharif Digital Repository

The effect of some inhibitors consisting of sodium nitrite (NaNO 2), sodium nitrate (NaNO 3), sodium molybdate (Na 2MoO 4), and sodium silicate (Na 2SiO 3) on the corrosion behavior of aluminum alloy 3303 (UNS A93303) in a water and ethylene glycol (C 2H 6O 2) mixture was investigated. In the first part, the tests were established without any galvanic coupling. In the second part, the tests were established with galvanic connections between the aluminum alloy and mild steel, stainless steel, copper, brass, and solder. Results show that the best corrosion inhibitor in both situations is sodium nitrate, according to its abilities to reduce corrosion rate, passivate the aluminum surface, and... 

Purpose: The purpose of this paper is to evaluate the galvanic corrosion of nitinol orthodontic wires with six dental alloys in artificial saliva and consider the effect of initiated localized corrosion and real surfaces of anode and cathode on galvanic current. Design/methodology/approach: Linear polarization and cyclic polarization curves for each alloy in de-aerated Duffo and Castillo's artificial saliva are obtained. Galvanic corrosion investigation is conducted by polarization curve intersection and mixed potential theory methods. In order to verify the initiation of localized corrosion, scanning electron microscopy is used. Findings: Initiation of localized corrosion on the anode... 

Joining of dissimilar light metals by friction stir welding (FSW) is of interest to reduce weight and fuel consumption in the transport sector. Such coupled metals may need protective surface treatments, e.g. against wear or corrosion, for some applications. In this work, the formation of plasma electrolytic oxidation (PEO) coatings in a silicate-based electrolyte for corrosion protection of FSW AZ31B magnesium alloy-titanium joints has been studied. The joints, if unprotected, may be susceptible to severe galvanic corrosion in chloride-containing environments. The coatings were characterized by scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Mg2SiO4 and... 

Magnesium and its alloys have gained significant popularity due to their light weight and their potential for use as bioresorbable materials. However, their application is limited in practice due to their relatively poor corrosion resistance. Several methods are available for improving the corrosion resistance of Mg alloys for bio-applications such as using different coatings, alloying, and modifying the microstructural parameters such as the grain size and the crystallographic texture. This review provides a comprehensive summary of the effects of crystallographic texture and twinning, as one of the most important deformation mechanisms of Mg and Mg alloys, on the corrosion behavior.... 

Application of corrosion resistant coatings is one of the most widely used means of protecting steel. Zinc coated (galvanize) steel, is well known for galvanic protection of steel substrates and nowadays, particular attention has been paid to the coupling of graphene oxide (GO) with metallic materials, in order to lessen corrosion rate. In this research, an isopropanol supercritical reducing environment prepared to make zinc ions bond directly with graphene oxides, to form a button shape hybrids of ZnO-Graphene (ZnOG). The hybridized bonding between zinc and graphene oxide is confirmed by Fourier Transform Infra-Red analysis. And the morphology revealed, using a Field Emission Scanning...