An Exception to Amontons' Law: The Friction of Carbon Surfaces in Air
P M. McGuiggan
The friction of carbon has been of much interest in recent years due to its good tribological properties. These properties include high wear resistance, high hardness, low friction coefficients, and low corrosion.1 In computer hard disks, the magnetic substrate is coated with 5 nm carbon and then coated with 0.8 to 1.5 nm Lubricant, typically a perfluoropolyether. To address this application, the friction of carbon must be studied at low pressures in air in order to mimic disk operation.