Wear resistance of arc ion-plated chromium nitride coatings

Wear resistance of arc ion-plated chromium nitride films has been studied. It has been found that texture and phases composing the films depend much on bias voltage and nitrogen gas pressure at the deposition. A phase diagram was constructed as a function of these two parameters, which indicated that three categories exist: CrN single, CrN and Cr₂N dual, and CrN and Cr dual phased regions, respectively. Results of Falex No. 2 test showed that the wear resistance of CrN single phased films is superior to others, especially when (220) preferred orientation is developed. Since hardness and surface morphology do not differ much between these films, a high toughness of CrN single phased film is considered to make a difference by suppressing abrasion wear.