Influence of calcium nitrate on morphology and corrosion characteristics of ammonium phosphate treated Aluminum coating deposited by arc thermal spraying process

Abstract

In present study Al coating was deposited by arc thermal spraying process thereafter treated with different concentration of Ammonium phosphate mono basic (NH4H2PO4) and 0.1 M calcium nitrate [Ca(NO3)(2)] to fill the porosity. Impedance values of treated coating was increased at longer duration of exposure in artificial ocean water due to transformation of Brushite and Ammonium Aluminum hydrogen phosphate hydrate into metastable and sparingly soluble gypsum and Aluminum phosphate. 0.1 M Ca(NO3)(2) has positive influenced with 1 M NH4H2PO4 on formation of compact and crystalline morphology as well as corrosion resistance of Al coating.