Substrate Preparation and Pre-Treatment

The object of surface preparation is to obtain the best performance and life of a bonded film for a reasonable expenditure of effort. In general bonded films will adhere to almost any surface which is clean and free of grease, oil and other 

The most important aspect of pre-treatment is probably to obtain the optimum surface roughness to give the maximum degree of mechanical keying of the coating to the surface. It is generally accepted that the optimum surface finish is between 0.5 fjm and 2.0 jjvn cla, and peak performances have been variously reported at 0.5 

Grit Material Mesh Size Surface Finish ( m rms) Wear life (minutes) 

Bonded Molybdenum Disulphide Coating (Data from Ref.338) 

Nitriding of steels is not in itself beneficial to bonded film performance, but Kawamura et al showed an interesting synergistic effect of soft nitriding and manganese phosphating on the wear life of a bonded molybdenum disulphide coating on an annealed steel. 

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