Effects of Deposition Temperature on Surface Morphology and Performance of Diamond-like-Carbon Coatings

A series of diamond-like-carbon (DLC) coatings were deposited on YG8 cemented carbide substrate by direct current plasma enhanced chemical vapor deposition (DC-PECVD) technology at different temperatures. The effects of deposition temperature on structure, surface morphology, thickness, micro-hardness, wear resistance and interface bonding performance of the DLC coatings were studied. The results show that the proportion of sp3 valence bond increased and then decreased with the increase of the deposition temperature, and the proportion was up to 69% when the deposition temperature was 160 ℃. The DLC coating would graphitizing at excessive temperature. The thickness, microhardness, wear resistance and interface bonding force increased and then decreased with the increase of the deposition temperature. When the deposition temperature was 160 ℃, the surface of the coating was smooth and compact, and the thickness, micro-hardness and interface bonding force were maximum, they were 3.2 μm, 2 395 HV and 63 N, respectively. The variation of the microhardness, wear resistance, thickness and interface bonding performance of the DLC coatings with deposition temperature was closely related to the content of sp3 valence bond.