Wear of Special Treated Tools During MDF Peeling

Abstract

Tools with chromium nitride coating applied by triode pulverizing have been tested in routing and peeling of wood. The efficiency of coatings was proved in medium density fiberboard cutting, thus in heavy cutting conditions , as well as in routing of OSB (Oriented Strand Board) where a CrN coating of 1µm of thickness allowed to process up to 9 times longer than in case of non-dressed tool [1]. The purpose of this study was to examine the improvement of the tools wear in the peeling of MDF, achieved by special treatment of the tool. The modifications of the active surfaces of knives by applying hard coatings (CrAlN, CrSiN), have already given the promising results in the routing of the MDF [2]. The limiting factor of applying these coatings is their adhesion to the substrate –the cutting tool. For this reason the duplex treatments including nitriding and hard coating deposition were tested Nitriding treatments have been performed inside a low vacuum furnace equipped with an impulsive current generator. The CrAlN coating was carried out by a dual magnetron sputtering system 8NORDIKO type 3500-1356 MHz. The CrSiN films were deposited using DC/RF dual magnetron sputtering system (AC450). In order to study the Si content effect on the CrSiN properties, two targets (50.8 mm of diameter) of Cr (99.99%) and Si (99.99%) were used. ADC and RF (13.56 MHz) generator were used to polarize the Cr and Si targets, respectively. The Cr target/substrate distance was 80mm while the Si target/substrate distance was only 70mm. The CrSiN coating have been prepared by institute FEMTO/ST of Besancon. The wood machining tests were performed using a laboratory microlathe which permits to make a simulation of the peeling process.