Finite element simulations of sliding contact of the head-disk interface in magnetic storage with lubricant effects

Abstract

Perfluoropolyether (PFPE) polymer lubricant performs an important role in protecting both the writing/reading elements in the recording head and the disk of magnetic storage devices from mechanical wear or damage, induced by direct contact. Under high-speed sliding, the nanometer thick lubricant shows complex behavior, such as shear thinning, slippage and bonding ratio, making it difficult to directly test or simulate its performance. Based on a numerical model, the present study obtains the mechanical response of the lubricant under normal and sliding contacts. The mechanical response is then entered into a finite element model (FEM) through definition of material behavior of the lubricant using a hyper-elastic constitutive model. By comparing the sliding contact simulations with lubricant and without lubricant, it is found that the presence of lubricant helps to reduce the contact stresses, mainly because the contact area is increased.

Keywords

• Molecularly thin lubricant
• Magnetic storage
• PFPE
• Finite element
• Head-disk interface