Performance comparison of green lubricants in gear hobbing with minimum quantity lubrication

It presents performance comparison of two green lubricants based on fatty alcohol and synthetic ester in hobbing with minimum quantity lubrication of spur gears using temperature generation at teeth hobbing zone (THZ), heat transfer mechanism, hob wear, gear quality, microhardness, and work hardening capacity. It is found that fatty alcohol-based lubricant yielded smaller THZ temperature, minimum hob wear, microgeometry deviations, and flank surface roughness and higher Prandtl number, microhardness, and work hardening capacity than synthetic ester-based lubricant. Higher Prandl number means friction reduction at THZ by forming a stable protective layer and heat dissipation by convection. Synthetic ester reduced THZ temperature by better cooling action. The outcome will aid in selection of better green lubricant to improve sustainability of hobbing.