The Effects of Primary Oxy-Salts on Anodizing Magnesium Alloy AZ91D

Abstract

Anodization is known to be an effective way to slow down the initial corrosion rate of magnesium (Mg) and its alloys. Here, we investigated the specific use of oxy-salts to improve the corrosion resistance of anodizing coatings. Oxy-salts of silicate, phosphate, and carbonate were added separately to a sodium hydroxide alkaline electrolyte used to anodize Mg alloy AZ91D. The process was investigated in terms of anodizing behavior, the surface properties, and the corrosion behavior of AZ91D. Anodizing AZ91D using the silicate-containing electrolyte generated sparks, and produced a thicker and more corrosion-resistant layer than the other oxy-salts. In the process, MgO and SiO2 formed Mg2SiO4 at high temperatures. Coatings from the phosphate-and carbonate-containing electrolyte anodizations did not contain phosphorus or carbon. We also studied the effects of silicate concentration on the corrosion resistance and properties of the surface.

Mechanical Properties Enhancement of AZ91 Magnesium Alloy Reinforced with Various Ratios of Titanium Particles and Processed by ECAP

“…Magnesium alloys and titanium alloys are widely used lightweight materials in industries such as aerospace, automotive, and healthcare. Magnesium alloys are known for their low density, strong mechanical properties and secondary process [1][2][3] though they have limited corrosion resistance [4]. While titanium alloys exhibit excellent corrosion resistance and high-temperature stability but are relatively heavy [5].…”