Tribology of solid-lubricated liquid carbon dioxide assisted machining
Franci Pušavec, Luka Sterle, Mitjan Kalin, Dinesh Mallipeddi, Peter Krajnik
Abstract
An investigation is made into the lubrication capabilities of solid-lubricated liquid carbon dioxide (LCO 2 ) in comparison to flood lubrication, straight LCO 2 and oil-lubricated LCO 2 (MQL). The coefficient of friction is determined via tribological experiments, similar to machining, using an open tribometer which features an uncoated carbide insert sliding against a workpiece. Tribological experiments reveal superior performance of solid-lubricated LCO 2 . The milling experiments as well indicate that solid-lubricated LCO 2 significantly reduces wear. The machined-surface topography is examined using high-magnification SEM, which shows no presence of adhered solid particles on the workpiece surface, providing a completely dry machining process.