Cailiao Baohu (May 2023)
Study on Friction and Wear Characteristics of Coating on Surface of WC Cemented Carbide and Its Milling Performance
Abstract
In order to investigate the friction and wear characteristics of nitride coatings on surface of WC cemented carbide and their effect on tool milling performance, TiN, CrN and TiAlN nitride coatings were deposited on surface of WC cemented carbide by physical vapor deposition (PVD). The microstructure and friction and wear properties of WC cemented carbide substrate and three nitride coatings were analyzed by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and friction and wear tester. The milling performance of WC cemented carbide and three nitride coated cutting tools was studied by using 45 steel as the milling material. Results showed that the nitride coating could effectively improve the surface hardness and wear resistance of WC cemented carbide substrate. Among the three nitride coatings, TiAlN coating had the highest hardness, which was 26.5% higher than that of WC substrate, and significantly improved the wear resistance of WC cemented carbide. The wear characteristics of TiAlN coating were small abrasive wear and slight oxidation wear. The high hardness and high wear resistance of TiAlN coating were more conducive to milling 45 steel. The oxide film generated in the milling process was easy to cover the surface of the tool tip, playing a significant role in protecting the tool surface and further improving the milling performance of the tool. Compared with other coatings, TiAlN coated tools had less chip adhesion on the back face of the tool, and showed strong chip removal ability, which was of great significance to improve the milling performance of the tool.
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