Tribology and application of Ti-C:H- and Cr-C:H-coated cemented tungsten carbide substrates

A series of Tix%-C:H and Crx%-C:H coatings on cemented tungsten carbide (WC-Co) substrates have been tested. Wear testing has been performed on an oscillating wear testing machine. Cutting performance was evaluated by practical milling trials on AISI 1045 steel. Microhardness, the percentage of elastic deformation energy, adhesion strength and elemental composition within the coating layer have been studied. The results are compared with uncoated and ceramic-coated WC-Co substrates. Experiments show that a Ti10%-C:H/TiC/TiCN/TiN/Ti coating provides excellent tribological properties for wear resistance, while a Ti30%-C:H/TiC/TiCN/TiN/Ti coating is the optimum coating for cutting performance. The Cr-based coatings (Crx%-C:H and ceramic coatings CrN, CrCN) yielded poor cutting performance.