Initial Study of the Effect of Some PVD Coatings (“TiN/AlTiN” and “TiAlN/a-C:N”) on the Wear Resistance of Wood Drilling Tools

Abstract

The wear of drills when processing wood-based boards is an important problem in industrial practice. The main objective of the study was to experimentally check whether two types of PVD coatings (multilayer nanocomposite “TiN/AlTiN” and double-layer coatings “TiAlN/a-C:N”) increase the wear resistance of the drill bits significantly (in terms of statistics). The typical two-blade drill bits intended for drilling in wood-based panels were used. During the experiments, the holes were drilled in samples made of commercial raw three-layer particleboard with the spindle speed of 4500 rpm, and the feed per revolution was 0.15 mm. The tool wear was monitored using a microscope. The advantage (greater resistance to wear) of both of the tested coatings (“TiN/AlTiN” and “TiAlN/a-C:N”) over raw cemented carbide was statistically significant in the initial period of machining (before 800 holes were drilled). Unfortunately, in the final period (when the number of holes drilled was over 800), only one coating (“TiN/AlTiN”) retained its advantage over raw cemented carbide. The effect of the second coating (“TiAlN/a-C:N”) turned out to be statistically insignificant.