The Improvement of CrN Coatings Wear Resistance by Adjusting the Cycle Number of Electrochemical

To further improve the sealing effect of electrochemical polarization (EP) on the CrN coatings, the EP treatment at different cycle numbers was conducted. The microstructure, mechanical, and tribological properties of CrN coatings were investigated. Findings indicated an elevation in oxygen content from 6.32% to 12.35% with increasing cycle number from 10 to 60 times, yet the crystal structure of CrN (111) and CrN (200) persisted. The X-ray photoelectron spectrum (XPS) and transmission electron microscope (TEM) revealed that a minimal quantity of oxides was produced. This led to a decrease in the coatings porosity from 16.79% to 5.83%. For this reason, the hardness of CrN coatings increased with a maximum degree of 18.3%, whilst the wear rate decreased with a maximum degree of 37.5% at the cycle number of 20 times.