Coupled temperature-displacement finite element analysis of a slider sliding contact with a textured disk surface and the critical condition for demagnetization

In order to develop the critical operating conditions for demagnetization of the disk, a coupled temperature-displacement finite element analysis of a slider sliding contact with a textured disk surface was performed, so as to investigate simultaneously the stress and temperature distributions in the magnetic layer. The flash temperature increasing with sliding distance was presented. The maximum magnitude of interior stress and temperature in the magnetic layer were responsible for the occurrence of demagnetization. The influences on the maximum temperature rise and stress due to the sliding velocity, contact pressure, frictional coefficient, and surface texture were examined. From the simulation results and the demagnetization temperature/stress available, the critical condition for demagnetization in magnetic recording disks was deduced. Sinusoidal surface texture produces a sinusoidal temperature distribution in transient sliding contact. Sharper texture produces larger temperature rise and stress in the magnetic layer. Effect of sliding velocity on the temperature rise is larger than that on the stress. Sliding velocity and slider pressure with maximum stress of the magnetic layer smaller than 1.2 GPa is the safe operating condition for the magnetic disk, but the maximum temperature of the magnetic layer higher than 180 K would lead to demagnetization.