Research On The Influence Of Head-disk Contact And Collision On The Dissipation Of Lubricant Molecules

Nowadays,with the rapid development of the data industry,the requirement for data storage is increasing.In order to increase the magnetic storage density of disks,the flying height between head and disk is decreased to a few nanometers.In such a small space,the possibility of contact between the slider and the disk increases.The head/disk contact will generate friction and induce heat,which will cause migration,loss,or redistribution of the lubricant.Furthermore,it may damage the disk permanently.As the mechanism of the effect of the contact between the slider and the disk on lubricant depletion is not clear,the factors that affect the transfer and redistribution of the lubricant molecules during the contact are investigated.The study is of great significance for the development of hard disk drives in the direction of high storage density,high accuracy,high reliability,and high stability.Therefore,this thesis established a finite element model and a molecular dynamics model of head/disk contact to calculate the generated heat due to head/disk contact.By comparison and analysis of the two models,the frictional heat generation characteristics of the head/disk contact are studied.The effects of the head interference depth and the disk velocity on the temperature rise caused by frictional heat were analyzed.Finally,the approximate range of the local temperature rise of the head/disk interface was obtained.A molecular dynamics model was developed to study the effect of the frictional heat generated by head/disk contact on lubricant transfer and depletion From a micro view,it was shown that during the contact process,the temperature rise has a significant effect on lubricant depletion.At the same time,the effects of disk velocity,and the pressure difference between the head and disk on the transfer and redistribution of lubricant molecules are simulated.The topography of the slider plays a major role on the lubricant transfer.Therefore,a molecular dynamics model with different types of slider,such as the shape of the head protrusion,was developed to study the effect of slider types on lubricant transfer.Specific,the effect of slider types on the penetration depth and lubricant depletion during the head/disk contact was investigated.The boundary pressure and the operating conditions were taken into account as well.This paper reveals the relevant process and results of lubricant molecule transfer and depletion during the head/disk contact.The mechanisms of lubricant transfer,the amount of lubricant depletion,and the lubricant redistribution when the head/disk contact occurs were discussed.In combination with the obtained factors affecting the lubricant molecules,an effective method for suppressing or eliminating the migration of lubricant molecules when a contact collision occurs is provided.It provides a reference for the design of the topography of the air bearing surface.The stability and reliability of the hard disk provide related technical support for the development of high density and high storage capacity.