Study On Performance And Preparative Process Of Graphite-Like Carbon Coating On Aluminum Alloy

Graphite-like carbon (GLC) is a kind of antifriction coating, which were prepared using the unbalanced magnetron sputtering system. The GLC coatings were deposited on aluminum alloy by changing plasma cleaning parameter, the deposited bias voltage and different adhesions. The surface imagines of aluminum alloy after plasma cleaning and the microstructures and different adhesion interfaces of the coatings were observed and analyzed by using scan electron microscope (SEM), transmission electron microscope (TEM), respectively. The micro-hardness, the adhesion intensity, and the tribological properties of coatings were measured by using a micro-hardness tester, a scratch tester and the pin-on-disc tester, respectively.The results of observation and analysis show that: After extending the cleaning bias voltage and time, the microetching action of the aluminum alloy substrate was aggravated. It was benefited for increasing adhesion intensity between the coating and the substrate and has affected the surface roughness. Good adhesion intensity and the minimum friction coefficient were tested. The parameter of the plasma cleaning was -400 V, 30min.With the increasing of the depositing bias voltage, the thickness of the coating decreases; however, the hardness and the critical load pre-increase and then decrease. The peak value happened at 65V.There is a major effect for improving the adhesion intensity between the GLD coating and the aluminum alloy substrate to elect the sublayers. The GLC coating which deposited Al sublayer expresses the excellent tribological properties and better adhesion intensity.