Effects of tungsten on the microstructures and tribological properties of CrN–Wx% coatings

CrN–Wx% coatings with different tungsten contents were deposited using unbalanced magnetron sputtering technology. The microstructures and mechanical properties of CrN–Wx% coatings have been characterized by SEM, X-ray diffraction (XRD), nanoindentation and adhesion techniques. The tribological properties of the coatings were investigated using an oscillating friction and wear tester under dry conditions. Indexable inserts with CrN–Wx% coatings were applied to turning AISI 1045 steel material by a lathe. Micron-drills with CrN–Wx% coatings were adopted in the ultra high speed (105 rpm) PCB through-hole drilling test. Experimental results indicate that the coating microstructure, mechanical properties and wear resistance vary according to the tungsten content. CrN–W6% coated tools showed the best wear resistance in 1045 steel turning and PCB through-hole drilling tests. The service life of CrN–W6% coated tool is three times greater than that of an uncoated tool in PCB through-hole drilling test.