Superhard, functionally gradient, nanolayered and nanocomposite diamond-like carbon coatings for wear protection

摘要

Recent progress in the development of advanced carbon-based tribological coatings is reviewed.Pulsed laser deposition (PLD) was used to produce superhard (60-70 GPa) self-lubricatingdiamond-like carbon (DLC) with low friction and low wear rate. Attention was given to theimprovement of coating toughness. A hybrid of magnetron sputtering and PLD was used to depositcoatings with architectures designed to withstand 1-10 GPa contact stress. This included: (1)composite coatings combining hydrogen-free and hydrogenated DLC (2) functionally gradientmetal-ceramic-DLC and nanolayered coatings with crystalline metal and carbide interlayers (about10 nm thick) between DLC layers (about 60 nm thick); and (3) nanocrystalline-amorphous compositecoatings with 10-50 nm diameter carbide particles encapsulated in a DLC matrix. The research led tothe fabrication of thin (2-3μm) DLC-based coatings for steel substrates which could maintainfriction coefficients of about 0.1 for several million cycles of unlubricated sliding at contact pressuresabove 1 GPa. Their scratch resistance exeeded that of conventional ceramic (TiN, TiC) coatings.