AMORPHOUS HYDROGENATED CARBON-FILMS FOR TRIBOLOGICAL APPLICATIONS .2.FILMS DEPOSITED ON ALUMINUM-ALLOYS AND STEEL

This paper describes the methods for the deposition of AHC films on al uminium alloys (2024, 7075 and an additional Al-Si alloy) and AISI 434 0 steel. Both unmodified and silicon modified AHC films were deposited . AHC films could be deposited on aluminium alloys without any interla yer. The deposition of AHC films on steel required an interlayer which could be aluminium, silicon or chromium. Thin films (1-2 mu m) deposi ted on aluminium alloys and steel influenced durability of films and f riction coefficients in contact with steel. These were believed to be due to plastic deformation of substrates. Deposition of a thicker coat ing system (interlayer + AHC) reduced friction coefficients and also i mproved film durability. The durability of films deposited on steel su bstrates was evaluated under both unlubricated and lubricated conditio ns for 5.5 million cycles under 4.4 N load and up to 2.5 m/s sliding s peed. Although there was wear, the films survived 5.5 million test cyc les under unlubricated sliding, but in the presence of two lubricants, the film wear was very small and could not be measured. It was observ ed that the wear of the steel counterface in contact with silicon-cont aining AHC films could be higher than that against an uncoated steel i n the presence of certain lubricants. Copyright (C) 1996 Elsevier Scie nce Ltd