Deposition technology, tribological properties and applications of superhard amorphous (ta-c) carbon films

Tetrahedral bonded amorphous carbon (ta-C) films are the hardest in the family of amorphous carbon films and possess sp3 contents up to 80%. Using high-current pulse-arc techniques in combination with an optimized film structure, ta-C films up to 10 µm thickness and hardness up to 60 GPa have been deposited onto steel substrates. The films are characterized with respect to their density, elastic modulus, adhesion, surface roughness, friction coefficient and wear resistance. Due to their unique tribological properties such films are successfully applied for wear protection of tools and components under critical lubrication conditions. The need for coating of larger series of tools and components leads to the development of an industrial applicable deposition equipment and technology. The result is the Laser-Arc-Module (LAM) technology, which can be combined with any conventional batch coater used in industry, irrespective of the manufacturer. The LAM consists of several components; the source chamber, the high current arc source with pulse power supply, the computer based control system and the laser unit including the igniting pulse laser and the optical system with the scanner. The advantage of this LAM concept is that he whole equipment and all functions of the basic coater (e.g. vacuum production, sample planetary, plasma cleaning technology, hard-coating deposition etc.) can be used and additionally a top-layer o f hard amorphous carbon can be deposited during the same cycle.