氦-空混合气体下热辅助磁存储头盘界面润滑剂迁移机理

Migration mechanism of lubricant at head-disk interface of heat assisted magnetic recording filled with helium-air gas mixture

为了提升硬盘读取数据的效果,进一步增加硬盘的存储量,对头盘界面空间散热的影响因素及其影响规律,以及氦-空混合气体环境下润滑剂的迁移规律进行研究,建立了磁头磁盘界面空间气浮轴承模型和热辅助下磁头磁盘界面空间润滑剂迁移的分子动力学模型,并以此为基础将气浮轴承模拟结果输入到模型中,探析氦气质量分数及其他影响参数对头盘界面空间散热的影响规律,以及激光热流及其他影响参数对氦-空混合气体环境下润滑剂迁移的规律。结果表明:氦气质量分数加剧了头盘界面空间的散热强度;与磁头飞行高度相比,润滑剂厚度、环境压强的增大更利于磁头磁盘界面空间的散热;润滑剂转移量随激光热流、磁盘速度的增大而增大;随着脉冲光斑尺寸的增加,润滑剂转移量先增加后减小,且光斑半径为20σ时润滑剂转移量达到最大值;Zdol2000,Zdol4000,Ztetraol2000及ZTMD等4种润滑剂中,Zdol4000造成的润滑剂转移量最大。研究获得的头盘界面空间散热因素及热辅助下影响润滑剂转移量影响因素的结果,能够为充氦热辅助硬盘的设计提供理论依据,也可为下一代磁存储记录技术的发展提供技术支持。

In order to improve the data reading effect of the hard-disk and further increase the storage capacity of the hard-disk,the factors affecting the heat dissipation of the head-disk interface space and the migration rule of the lubricant in the helium-air mixed gas environment were studied.The air-floating bearing model and the molecular dynamics model of lubricant migration for heat-assisted magnetic recording at the head-disk interface were established.The simulation results of air bearing model were input into the molecular dynamics model to analyze the influence rules of helium fraction and other influencing parameters on the heat dissipation at the head-disk interface,as well as the influence of laser heat flux and other parameters on lubricant migration in helium-air mixed gas.The results show that the heat dissipation intensity of the head-disk interface increases with the increase in helium percentage.Compared with the flying height of the head,the lubricant thickness and the ambient pressure are more conducive to heat dissipation.Furthermore,lubricant transfer increases with the increase in laser heat flux and disk velocity.However,with the increase in pulse spot size,the amount of transferred lubricant increases first and then decreases,and the maximum lubricant transfer occurs if the laser spot radius is 20σ.Compared with Zdol2000,Zdol4000,Ztetraol2000,and ZTMD leads to the maximum lubricant transfer.The results obtained by this study can provide theoretical basis for the design of helium-filled thermal assisted hard disk and technical support for the development of the next generation magnetic storage and recording technology.