NOVEL HIGH WEAR-RESISTANT DIAMOND-LIKE CARBON COATINGS DEPOSITED BY MAGNETRON SPUTTERING OF CARBON TARGETS

A series of new diamond-like carbon (DLC) coatings has been produced b y magnetron sputtering using in-house equipment. The new hydrogen-free pure carbon coatings were deposited by sputtering carbon targets in a pure argon atmosphere. With a metallic interlayer, they have shown im proved tribological properties when compared with conventional hydroge nated DLC in pin-on-disc and reciprocating wear tests. The films have also shown the ability to perform in oil, water and dry environments, and to protect the counterpart. The method of ball cratering on wear t racks provided taper sections to allow the analysis of coating wear, i nterface condition and failure mechanisms. Wear rates as low as 3 x 10 (-17) m(3)/N m are shown for 100 N, 10 000 cycle reciprocating wear te sts in air and in water. Scratch tests have been used to assess coatin g adhesion with critical loads as high as 70 N. Results from nano-inde ntation, Raman spectroscopy, electron energy loss spectroscopy and X-r ay diffraction are also reported.