Influence of WC-Co knifes pre-treatment with drag finishing method subjected to tool coatings deposition on blunting process

Abstract

ABSTRACT This paper details the analysis of the micro geometry in modified tools coated with the nano multi-layer TiN/AlTiN obtained by the PVD method. In standard replaceable cutting blades made of WC-Co before deposition, the radius of the blade rounding was increased from about 4 µm to about 13 µm using the drag finishing method with usage of OTEC company device. Next, the tools coated with the multilayer nano-coating TiN/AlTiN were subjected to blunting process. Mentioned above procedure was carried out on a standard 18 mm thick chipboard, assuming the blunting criterion (maximal tool wear on clearance face) Vbmax = 0.2 mm. In addition, previously blunted tools (modified and unmodified) were subjected to a detailed geometric analysis on a contact profilometer. Results show significant differences in the changes of various geometric parameters, in particular in the coefficients determining the asymmetry of the edge roundness denoted with letter K. Especially analysis of changes that concerns coefficient KR based on loss of cutting edge from rake face in comparison to clearance face suggests more intensive abrasive tool wear on rake face. Based on durability tests it can be supposed that changes in values of asymmetry coefficients in general described with letter K can decide about tool life.