POSSIBILITY OF INCREASING THE LIFETIME OF THE CHOPPING KNIFE BY APPLICATION OF PVD COATING EVALUATED IN LABORATORY CONDITIONS

Abstract

A wood is a heterogeneous material and its elements adversely affect the process of its processing. This also significantly affects the service life of tools during its processing. The aim of the contribution was, based on laboratory tests, to assess the suitability of the application of the selected coating on the chopping knife. After the basic analysis of the chopping knife, the CROSAL+ (AlCrN) coating was designed, which is an improved variant of the successfully used first generation CROSAL coating. In the experiment, samples from two knives made of tool steel X48CrMoV8-1-1 were analyzed. One sample was uncoated and the other coated. Based on the results of laboratory analyzes and tests, namely basic macroscopic and microscopic analysis of samples from tools, with semi-quantitative EDX analysis to determine the presence and content of individual chemical elements on the base material - substrate. Furthermore, the samples were tested for resistance to abrasive wear according to GOST 23.208-79. Relative resistance to abrasive wear ψabr was assessed. and hardness coefficient KT. HV and HRC hardness measurements were also carried out to determine the difference in hardness between uncoated and coated knife samples. In conclusion, it can be concluded that from the analysis and results of the measurements, the given coating for the process of processing wood by chopping can ensure the extension of the life of the tool and ensure the sufficient quality of the produced chips.