Anisotropic tribological properties of the coating on a magnetic recordingdisk

Mechanical and analytical tools were used to characterize the coatings on a magnetic recording disk. The mechanical and tribological properties of the coating were evaluated using the nano-indentation and nano-scratch tests. The transmission electron microscopy (TEM) and the Auger electron spectrosc opy (AES) were used to determine the thickness and elemental compositions o f the coating layers, while the atomic force microscopy (AFM) was used to s tudy the surface topology and roughness. It was shown that the disk surface had a texture preferentially oriented along the circumferential direction with fairly uniform summit height and little waviness. The variations of su rface roughness data were analyzed statistically, based on the Gaussian pro bability and Weibull cumulative probability theories. The coefficient of fr iction and the surface roughness were found to depend on scan direction rel ative to the coating texture. The hardness and elastic modulus were strongl y influenced by the coating/substrate interaction and the surface roughness of the coating. (C) 2000 Elsevier Science S.A, All rights reserved.