Ultrahard Multilayer Coating Comprising Nanocrystalline Diamond and Nanocrystalline Cubic Boron Nitride
Ultrahard Multilayer Coating Comprising Nanocrystalline Diamond and Nanocrystalline Cubic Boron Nitride
Cubic boron nitride (cBN) is only second to diamonds in terms of hardness and thermal conductivity. However, cBN films are usually thinner and are grown on many substrates, which undermine their hardness, adherence and stability. The multilayer coating (MLC) developed by CityU overcomes the problems mentioned above by reducing the amount of cBN used and enhancing the superlattice strength. A reduction in film stress contributes to improved coating properties, making MLC an ideal material for processing cutting tools. The MLC is formed on a substrate, which comprises a base layer, and multiple nano-cBN and nanodiamond layers. Nano cBN layers are grown on nanodiamond crystallites using ion-assisted physical vapor deposition, ion-assisted plasma enhanced chemical vapor deposition, and nanodiamond deposition.
•Reduced film stress
•Low friction coefficient
•High adhesion, stability, and wear resistance
•Excellent thermal conductivity
19/07/2007
11/880,115
香港
