Wind power electricity generation is getting attention because of its eco-friendly, green energy production. However, premature bearing failure allied with wind turbine gearbox (WTG) bearings reduces the life span of the wind turbine and increases the cost per unit of energy. A common cause for this premature bearing failure is the formation of white etching areas (WEAs) and white etching cracks (WECs). This mode of catastrophic failure lowers the life span of WTG to less than 24 months from the designed life expectancy of 20 years. Therefore, it is vital to mitigate the premature bearing failure in the WTG bearings to expand the wind energy market and reduce the carbon footprint as well. WEAs/WECs mitigation can primarily be accomplished in three ways. The remedies include changing the bearing material, surface engineering methods, and varying the gearbox oil lubricant chemistry. The current study investigated the performance of hydrogenated diamond-like‑carbon (DLC) coating against WEAs formation under sliding-dynamic conditions. The results obtained show the capability of the proposed coating to delay the formation of white etching areas in the bearing steel under dynamic loading. Further, this work includes the performance of base oils with various lubricant chemistry against microstructural decay in DLC-coated AISI 52100 bearing steel. The effect of base oils against WEAs formation in DLC-coated steel is explored by analysing the condition of oils, wear behaviour, and subsurface microstructural change.
Keywords: Diffusible hydrogen, DLC coating, dynamic loading, white etching area