Lubrication performance of GQDs@PNIPAM microgels for titanium alloys

The tribological behaviour of YG8‐cemented carbide/Ti6Al4V (YG8/TC4) contacts under aqueous lubrication was investigated in this work. Three types of nano‐additives including poly (N‐isopropylacrylamide) (PNIPAM), graphene quantum dots (GQDs), and GQDs@PNIPAM microgels were prepared for use as water lubricant additives. Tribological tests were conducted at different concentrations of nano‐additives using a ball‐on‐disk reciprocating tribometer. The experimental results show that GQDs@PNIPAM has the optimum lubricating performance, the average friction coefficient decreases by 28.7% and the average cutting wear volume of the TC4 disk increases by 29.5% when the concentration is 1.5 wt.%. This provides a new strategy for the cutting of titanium alloy materials, which not only reduces the friction coefficient, but also increases the cutting wear volume of the TC4 disk, thereby improving the machining efficiency.