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

摘要

Single-grit rotating scratch tests have been conducted with a conical diamond 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 microscopes. It was observed that the adhesion between the tool and the deformed material and the hardening properties of material play active roles in the scratching 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 process. These parameters were found to be sensitive to the depth of cut, thus validating the close correlation to the size effect of overall specific energy.