Effect of electromagnetic voltage on wear resistance of CrAlN coatings

Abstract

In arc-ion plating, the droplets ejected from the cathodic target inevitably contaminate the coating with macro-particles (MPs), causing defects that usually reduce the mechanical properties of the coating. Normally, MP formation is suppressed by electromagnetic filtration technology. To investigate the influence of the electromagnetic field on the structure and mechanical properties of coatings, this study applied various electromagnetic voltages (0-45 V) in the arc-ion plating preparation of CrAlN coatings. The proportion of MPs in the coatings was effectively reduced by adding the electromagnetic voltage, and was minimized at 25 V. The wear resistance of coatings was also comparatively studied. The wear of all coatings followed the same abrasive wear mechanism, but reducing the number of MPs improved the wear resistance. The enhancement of wear resistance was attributed to the improved fracture toughness of the coatings with fewer MPs.