Effects of Laser Remelting Process on Microstructure and Wear Behavior of WC Coating Sprayed by HVOF

ABSTRACT

The wear of industrial and agricultural components and equipment represents a major factor of depreciation of capital and source of expenses with maintenance and replacement of mechanical components. As the wear is an essentially superficial phenomenon, involving the undesirable mechanical removal of surface materials, the solution studied in this work was to analyze the abrasive wear behavior of a surface coated with Tungsten Carbide (WC) sprayed by the thermal spray method by High Velocity Oxygen Fuel - HVOF on a SAE 1020 steel substrate. To improve the adhesion between the coating and substrate, to reduce the porosity present in the coating and to obtain better results in the abrasive wear test, a CO₂ laser treatment with a power of 125 W was applied to the surface of the WC coating. The samples coated by HVOF and HVOF + CO₂ laser treatment were characterized by Scanning Electron Microscopy (SEM) to evaluate the morphology and microstructure of the coating and interface, microhardness analysis, wear and roughness test were done. It was obtained as a result that the sample coated by the HVOF method showed a better performance in tests of microhardness, wear and roughness compared to the sample treated with the laser.

Keywords
thermal spray; wear; HVOF; laser