Atomic-scale structure and composition of tungsten carbide reinforced diamondlike carbon films

This study presents the true atomic-scale structure and composition of hard/lubricious nanocomposite diamondlike carbon (DLC) films. Nanocrystalline tungsten carbide (similar to 2-4 nm precipitates) in mixed sp(3)/sp(2) amorphous C-H matrices was characterized using the combination of three-dimensional atom probe (3DAP) tomography and transmission electron microscopy. Excellent correspondence in structural and chemical layering was observed (alternating similar to 25 nm thick carbon-rich and tungsten-rich layers) with 3DAP also revealing C(3)(2+) and C(2)H(4)(+) species in the carbon-rich layers and W(2+), WC(2+), C(+), and C(2+) species in the tungsten-rich layers. 3D morphology and chemical partitioning of the WC nanoprecipitates in the tungsten-rich layers are also discussed. (c) 2008 American Institute of Physics.