Micromechanical and tribological characterization of hard amorphous carbon coatings as thin as 5 nm for magnetic recording heads

Amorphous carbon coatings are employed to protect magnetic coatings in thin-film magnetic recording heads against wear and corrosion. These coatings have to be thin (5-20 nm) in order to minimize loss of read back signal amplitude. Micromechanical and tribological characterization of ultra thin amorphous carbon coatings of 5, 10 and 20 MI thickness, deposited by ion beam deposition technique on Al2O3-TiC substrate was conducted. Hardness, elastic modulus and micro/nano-scratch resistance of these coatings were measured using a nanoindenter. Friction and wear properties were measured using an accelerated ball-on-hat tribometer. The protection mechanisms of the coatings to the Al2O3-TiC substrate are discussed. These coatings were found to be very wear and scratch resistant and should find use in magnetic recording heads. (C) 1998 Elsevier Science S.A. All rights reserved.