A study on corrosion resistance of Sodium Metavanadate (NaVO3) coated on AZ91D Magnesium alloy by anodizing technique

Abstract

Anodizing also known as anodic oxidation coatings have attracted significant interest in the study because of their potential to improve the corrosion resistance of alloys. Anodic oxidation coatings are usually chosen for special applications heavy duty corrosion resistance is required. Previously, chromate compounds were widely used for producing conversion coatings to protect most metallic surfaces such as aluminum, steel and magnesium alloys. In spite of its toxicity hexavalent chromate (IV) has remain an essential ingredient in the metal finishing industry for corrosion control. But combining the economic impact of corrosion damage, the environmental and health problems caused by hexavalent chromate (IV), and the increasing the regulatory restrictions, scientists have a huge incentive to develop a new generation of environmentally friendly protective coating systems. The objective of this research is to determine the corrosion resistance of AZ91D magnesium alloy utilizing sodium metavanadate (NaVO3). Besides, to study on surface microstructure, thickness, surface roughness and chemical composition related to the coating and its contribution to corrosion performance. Then, investigate the corrosion behavior and corrosion protection mechanism of AZ91D magnesium alloy. Sodium metavanadate (NaVO3) is used as anelectrolytesolution to form coating in this research.