Production of Wear Resistance Coatings on CK45 Steel Surface by Electrospark Method

In this investigation, different coatings on CK45 steel surface was applied by Electro spark method. Using two kinds of electrode including hard facing chromium-steel electrode and Ni-TiC composite electrode, microstructure and tribological properties were investigated. The scanning electron microscopy (SEM) was used to characterize the product. Tribological properties of the coatings were studied by wear test. SEM photographs show that uncoated sample has a lamination wear mechanism unlike of coated samples with scratch wear mechanism. Composite coating has a lower wear than chromium-steel coating because of uniform distributed TiC particles in the nickel matrix as reinforcement. Results of the wear tests indicated that the uncoated sample has friction value about 0.31 whereas composite coated sample had 0.165 friction value. Uncoated sample experience shear, tensile and compressive stresses which may lead to failure by cracking and spalling. Wear mechanism changes by coating application from delamination to scratching and cause to lower abrasion.