Wear-resistant steel surfaces obtained by high dose implantation of carbon

Abstract Carbon ions were implanted into hardened and unhardened Sverker 21 and Thyrapid 3243 steels with doses ranging between 0.5 × 10 10 and 2.0 × 10 18 C + cm −2 and with ion energies of 75 and 150 keV. Friction and wear were measured with pin-on-disk tribometers, both unidirectional and reciprocating. The coefficient of friction was moderately reduced, from about 0.8 to 0.2–0.5, by the surface modification induced. In several cases a dramatic decrease in wear was observed. The wear behaviour was very dependent on the tribological test conditions (unidirectional or reciprocating test, relative humidity and test atmosphere (air, O 2 or N 2 )). Stoichiometry and structural properties were investigated with Auger analysis, transmission electron microscopy and selected-area electron diffraction. The ion-carbonized surfaces were amorphous, and peak carbon concentrations of up to around 90 at.% were measured. The main part of the implanted carbon was present as graphite or amorphous carbon.