Material removal and tribological behaviors of fused silica scratched by Rockwell indenters with different tip radii

Abstract Material removal and tribological behaviors of fused silica (FS) were studied by scratching under Rockwell indenters with various tip radii, aiming to find scientific clues to understand microscopic removal mechanisms of hard-brittle materials. It was found that the elastic depth took the main part of the total scratched depth of FS, while the remanent depth became obvious only under the smallest indenter. Coefficient of friction (CoF) had a sharp increase at the velocity of 200 mm/min in most circumstances, and plastic removal without cracking of FS could be obtained at higher velocities under the smallest indenter. The ploughing model could analyze the ploughing and adhesion parts of CoF during scratching, although overestimated the ploughing one for FS. It was deduced that during scratching on FS, variations of CoF were mainly attributed to adhesion, while plastic removal of the hard-brittle FS was facilitated by higher pressures and higher velocities.