Wear Behavior of Pure Titanium Coated With WC-Co by the Use of Electrospark Deposition Method

Abstract

Titanium is a highly interesting material in engineering because of its unique combination of high strength to weight ratio, excellent resistance to corrosion, and biocompatibility. However, the material’s low wear resistance, which is its inherent nature, limits its application in highly erosive conditions. In order to enhance the wear resistance of biomedical grade titanium with the help of a WC-Co coating, an electrospark deposition method was used in this work. The goal of this work is to investigate the effect of frequency and current upper limit in the electrospark deposition process on substrate properties. Hardness of the layers was measured by a microhardness tester. In order to study the morphology and microstructure of surface layers, scanning electron microscope was used. Tribological tests were conducted under technically dry friction conditions at a load of 12.5 N by a pin-on-disk tribometer. Titanium was observed in coating and metallurgical bonding between the coating and the substrate. The optimized sample's hardness was about 930 HV 0.1. Results showed that the presence of a carbide layer on the surface of titanium leads to a great enhancement of wear resistance of about 68% in the pin-on-disk test.