Metrological analysis of changes in the surface morphology of planer knives after working surface modification

The article focuses on the analysis of changes in the surface morphology of planer knives modified with four different anti-wear coatings: multilayer, monolithic, monolithic-gradient, and gradient. The coatings described in the article affect the extension of planer tools service life in the range from 153 to 269%. The main objective of the paper was to determine the effect of vacuum-plasma modification of working surfaces of tools intended for machine processing of wooden parts on their geometric structure. The research was carried out on planer knives made of HS6-5–2 high-speed steel and used in industrial conditions. The present work sums up the knowledge resulting from the exploitation tests of modified knives with the features defining the morphology of their working surfaces. The paper comprehensively characterizes the 3D surface roughness parameters, as well as other characteristics such as isotropy and depths histogram. The knife surface modified with a gradient coating (longest life 269%) had a high level of anisotropy. Rose directions with texture directions present that this kind of coating generated structure with 4.23% value of isotropy. The distribution of ordinates was characterized by high clustering and an negative skewness (Ssk =  − 0.74). The results described can be used in the design and quality assessment of thin anti-wear coatings, as well as in preparation of substrates for their application.