The Performance of Ceramic Enamels Containing CoO-Additives


Ceramic coatings (enamels) are normally to protect and isolate metallic surfaces against aggressive environments. In the present work, a set of low alloy steel plates are coated with a special ceramic – glass layer. The stability of which is investigate in terms of its nature adhesion, and the nature of the protected metal surface. These are considered to control the final performance of the laminated composite. Factors which are investigated are those related to the mechanical integrity of ceramic coat, like the porosity, hardness, glossiness, and thermal resistance. And those related to the state of bonding between the metal surface and the protective coating like adhesion index, coat thickness, and the percentage of carbon present in the low alloy steel surface. Moreover, the corrosion behavior of the coated metal surface was studied to investigate the performance of this protective barrier. During this work some measures were taken in an attempt to modify and develop this protective barrier by adding of various amounts of CoO to the basic ceramic mix of coat.It is notice that the overall coat thickness would progressively reduce stability and encourage the pore formation. However the addition of CoO to a certain limit of concentration has progressively enhanced the adhesion with metal surface, the glossiness of the ceramic barrier, its thermal resistance.