EFFECT OF TOTAL ACID CONTENT ON COATING MORPHOLOGY IN THE PHOSPHATING PROCESS

Abstract

In this study, the properties of phosphate coating applied to the surface of a metal substrate were investigated. Phosphate coatings consist of thin crystalline layers formed by different processing processes, such as zinc, iron and manganese. These layers form a porous and rough surface, making them suitable for various applications. While they are generally applied to materials such as carbon steel, low-alloy steel, and cast iron, some difficulties may be encountered in high-alloy materials. Zinc phosphate coatings are ideal for improving corrosion resistance and subsequent painting processes. Manganese phosphate coatings are particularly popular in certain applications, providing wear resistance and oil retention properties. However, the risk of corrosion may increase if phosphate coatings are damaged because these coatings are not self-healing. This study will investigate the effect of different acid concentrations on coating properties, focusing on the zinc phosphating process. The results of this study can make an important contribution to optimise phosphate coatings and better protect steel surfaces.