Nano-mechanical and nano-tribological characterization of Ni-Co-BN nano-composite coating for bearing applications

In this study, BN with the addition of Ni and Co have both been deposited on Aluminium-Silicon using the PVD technique. The composition and morphology of Ni-Co-BN coatings were investigated using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Mechanical studies on Ni-Co-BN coatings at low loads ranging from 500 to 1250 mu N were conducted to inves-tigate the effect of load on reduced modulus and hardness. Besides this, nano-wear studies were carried out with loads varying from 0.5 N to 1 N to investigate the distortion and cracking behavior of the coating. The results show that the reduced modulus and hardness of the Ni-Co-BN coating decreases as the load increases. The wear rate of the Ni-Co-BN coating increases with an increase in load from 4.08 x 10-5 to 1.608 x 10-4 mm3/m. The Ni-Co-BN coating displayed smooth wear scars on the sample surface with no fractures or debris, suggesting that the coated material flowed in a plastic way near the wear scar. The behaviour of the coating suggests its strong suitability for bearing applications.

Automated summary

In this study, Ni-Co-BN coatings were deposited on Aluminium-Silicon using the PVD technique and their composition and morphology were investigated. Mechanical and nano-wear studies were conducted to understand the effect of load on reduced modulus, hardness, and wear rate of the coating. The results showed a decrease in reduced modulus and hardness with increasing load, while the wear rate increased. The smooth wear scars on the coated material suggested its suitability for bearing applications.