S Hosseini - Department of Polymer Engineering and Color Technology, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
M.M Attar - Department of Polymer Engineering and Color Technology, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran

Different methodsareinvestigatedtoevaluatephosphatingprocesscompletion such as weight-time data, measurement of potential, adhesion by pull-off and Atomic Force Microscopy (AFM). These different methods were compared and alsophosphating coating completion time was obtained for zinc phosphating on steel 37.The optimal method depends on the facility. The best completion method is method that has short response time,acceptable response and low cost.The results indicated that increasing the phosphatingtime facilitated the precipitation of coating and also enhanced both thickness and uniformityof the coating. The best results were observed after 25 min of phosphating.

phosphatingprocess,completion methods, weight-time data, adhesion measurement, open circuite potential, Atomic Force Microscopy