Diamond-like carbon film deposited on stainless steel and a hard alloy substrate by the anode ion beam technique

Diamond like carbon films were deposited by the anode ion beam technique on stainless steel (SKD11) and a hard alloy of W and Co (YG6) substrate. The microstructure and morphology of the films were investigated by scanning electron microscopy, atomic force microscopy and Raman spectroscopy. Their mechanical and tribological properties were studied by a WS-2005 scratch tester, a Rockwell hardness tester and a ball-cratering tester. Results show that the films are smooth and dense. The surface roughness (Ra) of the films is around 5.2 nm. The content of sp3 bonds of the film on SKD11 (ID/IG=0.69) is higher than that on YG6 (ID/IG=1.54). The bond strength of the film on SKD11 (17.8 N) is lower than that on YG6 (39.2 N). There are only minute radial cracks on the film on YG6 while the film on SKD11 is peeled off after Rockwell hardness testing. The wear rate of the film on SKD11 (1.40E-4) is higher than that on YG6 (8.81E-5) as revealed by the ball-cratering tests.