Measurement of Impulsive Forces Arising from Flying Head/Disk Collision in Magnetic Disk Storage Systems

Abstract

A new method of measuring impulsive forces arising from flying head/disk collision has been developed for tribological studies of head/medium interface. In this method it is possible to obtain impulsive forces as impulses in two directions quantitatively. The measurement results show that these impulses are in the order of 10^-6 [N.s], and that the impulse perpendicular to the disk face is proportional to the elastic coefticient of the air film. Moreover, in the case of a sputtered disk, flying head/disk contact time can be measured, so that it is possible to obtain a first approximation of contact force in one direction from the impulse. From this measurement, contact force in direction tangential to the disk surface is estimated to be in the order of 10^-3[N].