ABSTRACT
Observations made on the prepared Si-DLC-coated 4340 steel specimens in the as-coated condition were similar to those reported previously [14]. Thus, the asdeposited coating thickness was fairly uniform and its average value increased with increasing beam current density. The average coating composition was measured by Rutherford backscattering spectrometry (RBS) for all elements except hydrogen, which was determined by forward elastic recoil analysis. The average stoichiometry of the as-deposited coating was C67Si9C>6Hi5Ar3 . Following a 30 min annealing at 200°C in argon the stoichiometry changed to C75Siio08H3Ar4. There were obviously a substantial loss of hydrogen, small increases in silicon, oxygen and argon contents and a significant increase in carbon. Coating thickness varied between 1.85 and 4.31 μτη and was reduced by about 7 pet after a 30 min annealing.
