Surface coating effects on contact stress and wear: an approach of surface engineering design and modelling

摘要

The present paper is a dedication to Professor Tom Bell, a distinguished scientist and engineer, for his great contributions and achievements in surface engineering design and modelling. An initial attempt has been made in surface system design through combining the authors' previous achievements in understanding contact mechanics of surface engineering system. The approach is taken mainly from modelling the contact behaviour of multilayer surface system with real rough surface profiles in terms of contact stress and deformation, and both boundary and finite element methods have been employed to understand the system contact behaviour. Experimental investigations have also been carried out on the performance of surface engineered gears (steel and titanium). Tests were carried out on untreated, TiN coated, plasma nitrided and duplex treated steel gears under dry running conditions, and it has been shown that the duplex system gives the best wear resistance. For titanium gears, experimental tests were carried out on untreated and thermal oxidised titanium against steel gears and the thermal oxidised treated has showed a significant wear improvement compared to that for the untreated specimens. Finally, possible further investigations have been proposed.