Tribological behavior of thermal- and pH-sensitive microgels under steel/CoCrMo alloy contacts

Abstract The tribological behavior of 316L stainless steel/CoCrMo alloy contacts under aqueous lubrication was investigated in this work. Three types microgels including poly(N-isopropylacrylamide) (PNIPAM), polyacrylic acid (PAA), and poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-co-PAA) were prepared used as lubricant additives solutions. Tribological tests conducted using a ball-on-disk reciprocating tribometer, over range temperatures, pH, concentrations the microgels. PNIPAM-co-PAA proven to have excellent anti-friction anti-wear properties, depending on temperature pH values maximum friction coefficient coincided with lower critical solution at 32 °C. At same time, increased increase value unique thermal- pH-sensitive properties provided new strategy for controlling wear lubrication.