Corrosion and wear performances analysis of PVD CrMoN/Cr coatings

Abstract

Tools coated CrN based alloys are currently used in several industries for machining and manufacturing but present severe wear, limiting their service life. Seeking an alternative, three CrMoN monolayers (~1-1.8 µm in thickness) coatings varying in the Mo percentage content were elaborated using the RF magnetron co-sputtering method. These coatings were evaluated and compared with the alloy currently used (CrN) by electrochemical tests in NaCl solution (stationary and no stationary methods) and sliding wear tests (ball-on-disc configuration) performed at room temperature. The results indicate that the samples coated with CrMoN presented better performance against wear and corrosion than the uncoated sample. Among the coatings, labeled C1 (27Mo at.%) showed the best corrosion resistance as it presents a positive corrosion potential Ecorr. However, the best wear resistance (lowest coefficient of friction) was shown by coating labeled C4 (33Mo at.%). All of the tested specimens underwent abrasive wear in addition to the adhesive wear.