DIAMOND FILMS DEPOSITED ON WC-CO SUBSTRATES BY USE OF BARRIER INTERLAYERS AND NANO-GRAINED DIAMOND SEEDS

Results on the structure, composition and properties of diamond films deposited onto WC-Co cemented carbides via special multilayer barrier interlayers preliminary seeded by nano-grained diamond particles are p resented. The barrier interlayers comprise a layer adjacent to the sub strate, which completely prevents substrate decarburization and Co dif fusion from the substrate, and a diamond-bonding layer needed to obtai n an enhanced adhesion of the PACVD diamond coating. Preliminary seedi ng the barrier interlayers with nano-grain diamond particles by use of a laser ablation technique allows a fine-grained, uniform and highly adherent diamond coating of high quality to be deposited by use of a c onventional PACVD technique. Results on the nature of the interaction between the diamond nano-grained seeds and barrier interlayer are also presented. (C) 1997 Elsevier Science S.A.