Local fluctuation of rigid magnetic disk durability

A method of friction, wear, and temperature-rise measurement in local areas of a disk surface with 30-μm resolution has been developed. An indenter-thermocouple is designed to measure temperature in the contact region. The indenter has a small contact area with the coating and forms a narrow track on the disk surface. The method allows detection of asperities and local peculiarities of the disk surface, where a disk/head failure can occur. The durability of rigid-disk coatings with different lubricant layers was studied. Microscopic investigations of the surface areas where deviations from the average tribology characteristics take place allow them to be related to local nonhomogeneities of coatings and lubricant layers. It is shown that peculiarities of tribological properties are connected with coating asperities of about 10 μm. The temperature-rise measurements give more information about the coating tribology than conventional friction-coefficient measurements