Tribological characterization of diamond-like carbon films on nonledeburitic high-speed steels

Hydrogenated diamond-like carbon (DLC) films were deposited on as-tempered nonledeburitic high-speed steel (NHSS) substrates (0-5-1-3Ti-2Nb grade) by capacitively coupled RF glow discharge in a methane atmosphere. The substra tes were cleaned with an argon flux before coating deposition. Coatings of 1-mum thickness, good smoothness and adhesion were successfully produced. M icroscale abrasive wear tests and field emission scanning electron microsco py were employed to evaluate wear resistance and morphology of the DLC film s, substrate-film boundaries and worn components. The wear coefficient of t he steel substrates was less than that of M2 tool steel, whereas that for t he DLC layer corresponded to the value previously reported for titanium alu minium nitride. Certain decohesion micromechanisms in the NHSS samples afte r microscale abrasion testing were similar to these found in fractured spec imens. Structural influences on the results are discussed. (C) 2000 Elsevie r Science Inc. All rights reserved.