Nanotribology on individual phases of duplex steel: combining roughness, material effects, and friction
Résumé
In this study, lateral force microscopy (LFM) technique was used to investigate local friction and wear behaviour on individual phases of dual phase steel. Important factors influencing friction interpretation at nanoscale are investigated. A nanoprobe made of silicon nitride (20 nm tip radius) was used for this investigation. The difference in phases is clearly apparent when the surface is smooth but with a slight increase in surface roughness, the frictional difference between the phases got masked. A clear direct dependence of friction force on normal force was observed at nanoscale as predicted by Derjaguin's friction model. This model appeared to be valid irrespective of the surface roughness modifications on different phases of the material. The tip wear phenomenon was detected through adhesion force measurements before and after the test. Even at nanoscales, the wear resistance was found to be directly dependent on the hardness of the phases.