Experimental Studies on Durability of PVD-Based CrCN/CrN-Coated Cutting Blade of Planer Knives Used in the Pine Wood Planing Process

Abstract

The condition of the cutting tool is one of the most important factors as it directly affects the technological and economic efficiencies of the woodworking process. The large variety of raw materials of wood combined with possible impurities and inclusion of solids puts high demands on planing machines. One of the methods to modify their operational properties is to apply antiwear coating on their working surfaces using vacuum deposition methods, such as physical vapor deposition (PVD). The use of such coatings reduces the adhesion of planing products to the surface of industrial planer knives, reduces the friction between the cutting tool and the workpiece, and limits the penetration of heat into the tool, thereby contributing to extending its effective working life. This study examines the impact of PVD-based CrCN/CrN coating on the operational durability and intensity of wear of planer knives operating in production conditions compared to unmodified knives (typically used in the wood processing industry for pine wood planing). For the unmodified and CrCN/CrN-coated planing blades (before and after processing), detailed analyses were carried out. These analyses included determining the rounding radius and profile along the blade (worn edge displacement), calculating surface texture parameters of the rake face of planer knives, and carrying out visual microscopic analysis of its condition. The results of the experiments indicated an increase in durability of up to 142% for the CrCN/CrN-coated tools. It was also found that the use of PVD-based modified industrial planer knives turned out to be more beneficial in each analyzed area of analysis.