Comparison Study of PVD Coatings: TiN/AlTiN, TiN and TiAlSiN Used in Wood Machining

In this paper, we analyze the possibilities of the protection of tools for wood machining with PVD (Physical Vapor Deposition) hard coatings. The nanolayered TiN/AlTiN coating, nanocomposite TiAlSiN coatings, and single layer TiN coating were analyzed in order to use them for protection of tools for wood machining. Both nanostructured coatings were deposited in an industrial magnetron sputtering system on the cutting blades made of sintered carbide WC-Co, while TiN single layer coating was deposited by evaporation using thermionic arc. In the case of TiN/AlTiN nanolayer coatings the thickness of the individual TiN and AlTiN layer was in the 5–10 nm range, depending on the substrate vertical position. The microstructure and chemical composition of coatings were studied by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) method. Additionally, in the case of the TiN/AlTiN coating, which was characterized by the best durability characteristics, the transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) methods were applied. The coatings adhesion to the substrate was analyzed by scratch test method combined with optical microscopy. Nano-hardness and durability tests were performed with uncoated and coated blades using chipboard. The best results durability characteristics were observed for TiN/AlTiN nanolayered coating. Performance tests of knives protected with TiN and TiAlSiN hard coatings did not show significantly better results compared to uncoated ones

Coatings deposited by physical vapor deposition (PVD) on high-speed steel used in the processing of wood materials

In this study the use of AlTiN/aCN, TiAlN/TiN and three types of CrAlN/CrN coatings deposited on HSS steel was investigated. These protective coatings were prepared using PVD (physical vapor deposition) method. The objective of this study was to compare the microstructure, chemical composition and properties of Cr, Al or Ti based coatings deposited on a substrate made of high-speed steel HSS. The thicknesses of coatings based on titanium were approx. 4 µm, and those based on chromium were less than 1 µm. The morphology and chemical composition were studied using scanning electron microscopy (SEM) and X-ray dispersion spectroscopy (EDX). The X-ray photoelectron spectroscopy (XPS) method was applied. The adhesion was evaluated by scratch test. Nanohardness and durability tests of uncoated and coated knifes were performed. It was found that the knifes made of HSS covered with two-layer TiAlN/aCN coating exhibited the best durability characteristic. Coatings containing chromium were less durable due to their small thickness. The highest nanohardness was found in the AlTiN/TiN coating due to its multi-layer nature. The nanohardness of the other coatings is comparable but more than two times lower compared to the multilayer AlTiN/TiN nanocoating