Friction-induced transformation of isopropanol at self-mated WC tribopairs and tribological performance of the in-situ formed carbon

Abstract Since the excellent tribological performance of polyhydric alcohols was reported under low loads, several polyhydric alcohols, such as glycerol, draw more attentions and was further investigated. However, the lubricity under high loads and fast rotational speed was rarely reported until now. In our previous work (Zhang R. et al, (2020) Applied Surface Science, 510, 145456) [1] , graphene was formed during sliding as selecting GCr15 ball being the tribopairs under 196 N and 600 rpm. Here, when we conducted the tribological tests of isopropanol under 98, 196 N and 1450 rpm using YG8 balls as tribopairs, to our excitement, amorphous carbon with high degree graphitization and WO3 nanoball were induced by tribochemical reactions that made the tribosystem exhibit extraordinary lubricity. WO3 nanoball was formed originating from the oxidation of WC tribopairs. The flash temperature rises and catalysts were two important roles for inducing amorphous carbon with high degree graphitization. However, the fabricated graphene exhibited poor lubricity compared to amorphous carbon induced by tribochemical reactions. This new find would be potentially applied in machinery and equipment.