Ion-implanted diamond films and their tribological properties

Abstract

Abstract This paper reports the physical characterization and tribological evaluation of ion-implanted diamond films. Diamond films were produced by microwave plasma, chemical vapor deposition technique. Diamond films with various grain sizes (0.3 and 3 μm) and roughness (9.1 and 92.1 nm r.m.s. respectively) were implanted with C + ( m/e =12) at ion energy of 160 eV and a fluence of 6.72 × 10 17 ions cm -2 . Unidirectional sliding friction experiments were conducted in ultrahigh vacuum (6.6 × 10 -7 Pa), dry nitrogen and humid air (40% RH) environments. The effects of C + ion bombardment on fine and coarse-grained diamond films are as follows: the surface morphology of the diamond films did not change; the surface roughness increased (16.3 and 135.3 nm r.m.s.); the diamond structures were damaged and formed a thin layer of amorphous non-diamond carbon; the friction coefficients dramatically increased in the ultrahigh vacuum (0.1 and 0.4); the friction coefficients decreased slightly in the dry nitrogen and humid air environments.