MECHANICAL PROPERTY AND ROLLING CONTACT FATIGUE LIFE OF TiN FILM ON BEARING STEEL BY PLASMA IMMERSION ION IMPLANTATION AND DEPOSITION

Titanium Nitride (TiN) films were synthesized on AISI52100 bearing steel surface employing plasma immersion ion implantation and deposition (PIIID) technique. X-ray diffraction (XRD) proves that TiN phase exists in the surface layer. The depth profiles and chemical bonds were analyzed with X-ray photoelectron spectroscopy (XPS) combined with Ar ion etching. Atomic force microscope (AFM) reveals that the TiN films have uniform distribution and good efficiency of space filling over large areas. The nano-hardness (H) and elastic modulus (E) of TiN films were measured, and the maximum H (E) value is 25 GPa (350 GPa), increases by 127.3% (59.1%). The friction and wear behaviors and the rolling contact fatigue (RCF) life of all these samples were also investigated by ball-on-disc and three-ball-rod testers. The results show that the friction coefficient decreases from 0.92 to 0.2 and the longest wear life increases by 16.5 times. The L 10 , L 50 , L a , and mean life L of treated sample increases by 5.5, 2.8, 2.3, and 2.2 times, respectively. It indicates that PIIID is an interesting technique in improving mechanical properties and RCF life of bearing steel.