Hard gradient (Ti,Al,Si)N coating deposited on composite tool materials

Purpose: This paper presents investigation of gradient coating of (Ti,Al,Si)N deposited on the Al2O3+SiC(w) oxide ceramics substrate deposited with the PVD process. Design/methodology/approach: Structure of substrate and coating was investigated with use of scanning electron microscopy (SEM); The X-Ray Photoelectron Spectrometry (XPS) and Auger Electron Spectrometry (AES) examinations was carried out for proving the gradient character of the (Ti,Al,Si)N coating. The investigation includes also microhardness and roughness tests of the deposited coating and used substrate. Scratch test results was analysed to introduce adherence of the investigated coating. Findings: Gradient structure and main properties of the investigated materials were introduced. It has been stated, that properties of the coated with gradient (Ti,Al,Si)N coating oxide tool ceramic increase in comparison with uncoated material. Practical implications: Depositing the wear resistant gradient coating onto the Al2O3+SiC(w) oxide tool ceramic results in a significant increase of the surface layer microhardness, contributing most probably in this way in machining to the decrease of the wear intensity of cutting tools’ flanks made from the Al2O3+SiC(w) oxide tool ceramic. Originality/value: Gradient coatings are an innovative idea. The composition, microstructure and properties of gradient materials change continuously from the surface to the interior of the material.