The Influence of Aluminum Oxide Particles in Magnetic Coating on Head/Disk Wear

The particulate magnetic disks commonly used in magnetic disk storage systems contain aluminum-oxide (Al2O3) particles to reinforce the strength of their magnetic coating. In this paper, the influence of these particles on the tribological characteristics of particulate disks is investigated using two types of ferrite materials for flying heads and particulate disks with four different levels of Al2O3 content. As the Al2O3 content increases, the wear mode changes from the adhesive wear to the abrasive wear. Owing to this transition, the head wear becomes increasingly severe while the durability of the particulate disk improves. Regarding the differences between ferrite materials, relatively soft Mn-Zn ferrite shows worse wear results than hard Ni-Zn ferrite. In particular, it is found that Mn-Zn fertile is worn even by the γ-Fe2O3 particles of the particulate disks. In the combination of ferrite materials and particulate disks used here, an Al2O3 content of around 8 percent is optimum to avoid headcrash, ...