Contact Characteristics of Spherical Head and Magnetic Disk Considering van der Waals Forces and Elastic Deformation of Contacting Asperities and Mean Height Surfaces

This paper presents a new numerical calculation method for head-to-disk contact characteristics, including the effects of van der Waals forces and elastic deformation of both asperities and mean height surfaces. Typical calculated results of disk deformation, spacing distribution, real contact pressure, attractive forces, external force, etc. are shown as a function of separation for a thermally protruded head model with a radius of curvature of 20 mm. From the calculated results, touchdown and scratch phenomena are discussed in relation to roughness parameters. It is argued that scratch durability can be improved by increasing the asperity radius and asperity density of the disk and head surfaces.