Investigating the microstructure and mechanical behaviors of DLC films on AISI52100 bearing steel surface fabricated by plasma immersion ion implantation and deposition

Abstract

The microstructure and mechanical properties of diamond-like carbon (DLC) films fabricated on an AISI52100 bearing steel substrate surface by plasma immersion ion implantation and deposition (PIIID) were studied. Atomic force microscope (AFM) observation reveals that the DLC film has an extremely smooth surface, and high uniformity and efficiency of space filling over large areas. Raman spectroscopy analysis indicates that DLC films are mainly constituted by amorphous and crystalline phases, with a variable ratio of sp2/sp3 carbon bonds, and sp3 bond content of more than 10%. The maximum nanohardness and elastic modulus of the DLC film are 40GPa and 430GPa, and increase by 263.6% and 95.5%, respectively. The friction and wear results exhibit that the friction coefficient against an AISI52100 steel ball decreases from 0.87 to 0.20. The corrosion polarization curves in a 3.5% saturated NaCl solution shows that the corrosion resistance of DLC/AISI52100 samples is much better than that of bearing steel substrate. Compared with the bare bearing steel, the surface mechanical property of the DLC/AISI52100 sample is improved significantly.