Effect of pulsed electromagnetic frequency on the microstructure, wear and solid erosion resistance of CrAlN coatings deposited by arc ion plating

In this work, the chromium aluminum nitride (CrAlN) coatings were prepared on TC11 titanium alloy by composite magnetic field cathodic arc ion plating with controllable pulse electromagnetic combined with permanent magnet. The effects of electromagnetic frequency on the morphology, microstructure, nano-hardness and elastic modulus of the coatings were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and nano-indenter. This paper has mainly studied the influence of CrAlN coatings which are prepared at various electromagnetic frequencies on the wear and erosion resistance through a series of wear and solid particle erosion experiments. It was found that the deposition rate of CrAlN coatings increases with the increase of electromagnetic frequency. And CrAlN coatings all preferentially grew along the (111) crystal plane. At 16.7 Hz, with the increase of pulsed electromagnetic frequency, the hardness is the highest (23.6 GPa) and the adhesion is the highest (41.5 N). In addition, the coating deposition exhibited the best wear and solid erosion resistance at 16.7 Hz and 33.3 Hz, the friction coefficient is about 0.35, and the erosion rate is about 0.2 mu m/g at 30 degrees and less than 1 mu m/g at 90 degrees, respectively. These results indicate that the CrAlN coating formed at an appropriate pulsed electromagnetic frequency can achieve excellent mechanical properties, wear and solid erosion resistance.