Characteristics of single-grit rotating scratch with a conical tool on pure titanium

Single-grit rotating scratch tests have been conducted with a conical diamo nd tool on pure titanium. The force profiles during the scratch event were captured using high frequency force transducers. The mechanisms of material removal have been characterized by optical and scanning electron microscop es. It was observed that the adhesion between the tool and the deformed mat erial and the hardening properties of material play active roles in the scr atching process. Adiabatic shear band (ASB) formation followed by cracking was observed to be responsible for the material removal during scratching. The overall frictional coefficient (OFC) was found to oscillate strongly at the beginning and at the end of the scratch, but increased steadily in the middle of the scratch. The size dependence of overall specific energy was observed and was mainly attributed to the competition between hardening and softening during the scratching process. Instantaneous specific energy and instantaneous scratch hardness have been introduced to characterize the pr ocess. These parameters were found to be sensitive to the depth of cut, thu s validating the close correlation to the size effect of overall specific e nergy. (C) 2001 Elsevier Science B.V All rights reserved.