Effect of Electrolytic/Chemical Pretreatment on Adhesion Strength of DLC Coatings on 304 Stainless Steel Substrate
To improve adhesion strength of DLC coatings on 304 stainless steel substrate,we studied substrate pretreatment by electrolytic/chemical etching methods.In this study,The DLC coatings were deposited on two groups of 304 stainless steel which had been electrolytically and chemically etched separately. The morphology of the coatings and substrate were characterized by SEM and metalloscope. The surface roughness of substrate was measured by roughness tester .The result shows that adhesion strength of DLC coatings on 304 stainless steel substrate is improved obviously due to mechanical interlock,surface adsorption and stress release.With prolonging the etching time,the adhesion strength of DLC coatings on the chemically etched substrate increase firstly and then decrease. The adhesion strength of DLC coatings on electrolytically etched substrate continuously increase. DLC coatings on electrolytically etched substrate perform better than the one on chemically etched substrate in adhesion.This is caused by the different surface morphology.