Structure and Wear-Resistance of Hardened Thin-Blade Knives with PVD Coating

A new technological process for hardening thin-walled knives 0.64 mm thick with a cutting edge of 0.1 mm used in the confectionery industry is proposed. For their hardening, the ion-plasma method of applying a nanostructured TiN multilayer coating was used. Statistical studies of the operational stability of such a tool in industrial production during crushing nuts have been carried out. By analyzing the results obtained, it was found that their operational durability varies over a wide range from 10 to 210 shifts. At the same time, the surface hardening coating with a thickness of 3.3 μm does not completely wear out. The main reasons for the failure of such a tool in operation are the insufficient quality of the metal products and processed products, which contribute to pore and crack formation, intensification of diffusion processes and the formation of zones of inhomogeneous distribution of phase components. Using modern methods, structural changes that occur during operation and affect the wear resistance of a thin-walled tool hardened with a nanostructured TiN coating are studied. The proposed integrated approach to quality control of the cutting tool in operation made it possible to identify changes in structure formation, the level of emerging stresses and degradation of the metal by the anisotropy of properties. Timely quality control of the tool made it possible to prevent the use in operation of knives with a large number of defects in the structure or an increased level of residual stresses.