Understanding evolution of tribo-chemical interfaces during boundary lubrication in manufacturing

Boundary lubrication during manufacturing processes especially at spindles, gears, machining interfaces, and other areas is an aggressive tribological condition resulting in the loss of energy, materials, and overall productivity. Nano-engineered lubricants have been explored to address lubrication challenges at nano/microscopic interfaces. However, lubrication mechanism at nano/microscopic interfaces is not fully understood. This paper reports investigation on tribo-chemical lubricant film formation mechanism using techniques of four-ball tribometer, SEM/EDS, Raman spectroscopy, and TEM to understand morphology, chemistry, and structure at interfaces as lubrication progresses over time. It was found that tribo-chemical film formation showed adaptive characteristics during lubrication for progressive surface protection. (C) 2017 Published by Elsevier Ltd on behalf of CIRP.