An investigation on the friction, wear and deformation of potassium dihydrogen phosphate

Abstract

This paper investigates the friction, wear and deformation of potassium dihydrogen phosphate (KDP) using the nano-scratching technique with both Berkovich and conical indenters. It was found that the indenter tip radius significantly affected the tribological properties of the material. Under a smaller tip radius (Berkovich indenter), the pill-ups were higher at the end of the wear/scratching tracks and friction fluctuation during nano-scratching was greater. The ploughing and brittle deformation dominated the wear mode under a larger tip radius (conical indenter). The KDP deformed in a ductile, ploughing or ploughing and brittle mode depending on the magnitude of the scratching load. The variation in friction coefficient was related to the wear mode and brittle deformation brought about a greater friction fluctuation. The crystal orientation (plane) also affected the behaviour of friction and wear of the material. The softer plane of KDP experienced more brittle deformation under both indenter types. The indenter tip radius had a significant influence on the surface morphology of KDP.