磁盘力磁特性和热力耦合作用下接触退磁行为研究
发布时间：2018-10-09 17:34
【摘要】：随着大数据时代的到来,硬盘存储技术作为信息的重要“载体”,其磁存储密度和磁记录速度得到了迅猛发展,于是磁头与磁盘的间距会不断降低。甚至为了实现1 Tb/in2以上的超高密度磁存储目标,其更是要降至2 nm以下,来保证磁头读写时高信号分辨率的需求。但是在如此狭小的空间内,一旦发生磁盘跳动、磁头随机振动、空气污染、润滑剂转移等情况,就很可能引起磁头/磁盘接触、造成磁盘内部塑性变形和快速温升的产生,从而导致接触界面失效、出现不可估量的数据丢失等问题。这样,磁头与磁盘的接触行为已经逐渐成为当前及未来磁存储设备数据丢失的重要原因之一。然而目前,与磁头/磁盘接触相关的磁学变化规律和磁盘退磁原因尚不明确,难以为避免磁头/磁盘接触退磁发生提供技术支撑。因此,本文采用微磁仿真方法、有限元方法以及实验手段,研究了磁头/磁盘接触的磁学行为,涵盖了以下几方面研究内容:根据塑性变形对磁畴的影响,本文从位错钉扎和残余应力两方面出发,利用畴壁钉扎模型与逆磁致伸缩原理分别推导了磁塑性能、磁应力能计算式。并在磁塑性能中,加入了矢量性特征、拉压性特征以及膜厚变化特征。于是,根据这两个能量计算式,就建立了基于微磁学理论的磁塑性模型。另外,还提出了基于微磁学理论的磁塑性模型的两种求解方法,由此完善了磁塑性模型的构建。本文利用纳米划痕实验模拟了磁头/磁盘接触的力磁行为,并通过磁力显微镜的相位成像原理,提出了一种定量探测方法,由此确定了磁盘的临界退磁条件和磁头/磁盘接触作用力、磁盘表面破坏程度及磁头/磁盘反复划刮次数对磁盘磁性变化的影响规律。随后,基于磁头/磁盘滑动接触有限元模型和磁塑性模型,揭示了实验研究无法获得的由磁头/磁盘接触的力磁行为导致的磁盘磁化演变过程。而且,采用磁盘介质力磁特性的实验与仿真结果的对比分析,有效地验证了构建的磁塑性模型的正确性。通过把随机热扰动项、Voronoi模型特征以及磁塑性模型相结合,本文建立了涉及热力耦合作用的Voronoi化微磁仿真模型,得到了温度影响下塑性应变/弹性应力的大小、方向性及拉压性与垂直磁记录介质磁化强度之间的依赖关系。继而,建立了磁头/磁盘高速滑动接触有限元模型,进一步揭示了磁头/磁盘接触退磁过程中磁矩偏转变化对磁性信息衰减的影响规律,并且获得了磁头/磁盘接触作用力、划刮速度对与转变噪声相关的介质SNR的作用关系。最终,利用不锈钢小球与磁盘的碰撞实验,确定了磁头/磁盘高速滑动接触有限元模型和Voronoi化微磁仿真模型的正确性。在磁头/磁盘接触作用下,本文通过改变磁盘介质的材料热力学属性、磁盘介质结构与材料磁学属性以及磁头/磁盘接触的界面参数,获得了磁盘介质抗接触退磁性能的影响规律,从而实现了提高磁记录层抗高温、抗高应力应变能力或者保持磁记录层良好记录状态的目的。特别指出,本文在考虑预防磁盘介质接触退磁问题的同时,还兼顾了“三难困境”的解决。
[Abstract]:With the advent of big data era, hard disk storage technology is important as information "Carrier" and the magnetic storage density and the magnetic recording speed are fast developed, so that the distance between the magnetic head and the magnetic disk is continuously reduced. Even in order to achieve the ultra-high density magnetic storage target of 1 Tb/ in2 or more, it is necessary to reduce the high signal resolution when reading and writing the magnetic head even below 2 nm. However, in such a narrow space, once disk runout occurs, magnetic head random vibration, air pollution, lubricant transfer, etc., it is likely to cause contact of the head/ disk, causing plastic deformation of the disk and rapid temperature rise resulting in failure of the contact interface, There are problems such as data loss and so on. In this way, the contact behavior of magnetic head and magnetic disk has become one of the most important reasons for data loss of current and future magnetic storage devices. However, it is difficult to provide technical support for magnetic head/ disk contact demagnetization. In this paper, the magnetic behavior of magnetic head/ disk contact is studied by using micro-magnetic simulation method, finite element method and experimental method, which covers the following aspects: based on the influence of plastic deformation on the magnetic domain, this paper starts from the two aspects of dislocation pinning and residual stress. Magnetic plastic energy and magnetic stress energy can be calculated by using domain wall pinning model and inverse magnetic resonance principle. In addition, the characteristics of vector characteristics, tensile properties and film thickness are added into the magnetoplastic energy. Thus, based on these two energy formulas, a magnetic plastic model based on micro-magnetic theory is established. In addition, two methods of solving the magnetic plastic model based on the micro-magnetic theory are also put forward, and the construction of the magnetic plastic model is perfected. In this paper, the magnetic behavior of magnetic head/ disk contact is simulated by nano scratch test, and a quantitative detection method is proposed by using the principle of phase imaging of magnetic microscope, thus defining the critical demagnetization condition of magnetic disk and the contact force of magnetic head/ disk. The damage degree of the disk surface and the influence of the number of repeated strokes of the head/ disk on the magnetic change of the magnetic disk. Subsequently, based on the magnetic head/ magnetic disk sliding contact finite element model and the magnetic plastic model, the process of magnetic disk magnetization due to the magnetic behavior of the magnetic head/ disk can not be obtained. Moreover, the correctness of the constructed magnetic plasticity model is verified by the comparison and analysis of magnetic characteristics of magnetic disk media and simulation results. By combining the random thermal perturbation term, Voronoi model characteristic and the magnetic plastic model, a Voronoi micro-magnetic simulation model involving thermal coupling is established, and the plastic strain/ elastic stress under the influence of temperature is obtained. the dependence of the directivity and the tensile force and the magnetization of the perpendicular magnetic recording medium. in turn, a finite element model of high speed sliding contact of a magnetic head/ disk is established, and the influence of magnetic moment deflection change on the attenuation of the magnetic information during the magnetic head/ disk contact demagnetization process is further disclosed, and the contact force of the magnetic head/ disk is obtained, The effect of scratch speed on the SNR of the medium associated with the transition noise. Finally, using the collision experiment of stainless steel ball and magnetic disk, the correctness of the finite element model of high speed sliding contact of magnetic head/ disk and Voronoi micro-magnetic simulation model is determined. Under the action of magnetic head/ disk contact, this paper obtains the influence law of anti-contact demagnetization performance of magnetic disk media by changing the material thermodynamics properties of magnetic disk media, the magnetic properties of magnetic disk media and the magnetic properties of materials and the interface parameters of magnetic head/ disk contact. thereby realizing the purpose of improving the high temperature resistance, the high stress response ability of the magnetic recording layer or keeping the good recording state of the magnetic recording layer. It is pointed out that this paper also gives consideration to the problem of preventing the contact demagnetization of magnetic disk media. "Three Difficult Position" a solution to the problem.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP333.3
本文编号：2260175
[Abstract]:With the advent of big data era, hard disk storage technology is important as information "Carrier" and the magnetic storage density and the magnetic recording speed are fast developed, so that the distance between the magnetic head and the magnetic disk is continuously reduced. Even in order to achieve the ultra-high density magnetic storage target of 1 Tb/ in2 or more, it is necessary to reduce the high signal resolution when reading and writing the magnetic head even below 2 nm. However, in such a narrow space, once disk runout occurs, magnetic head random vibration, air pollution, lubricant transfer, etc., it is likely to cause contact of the head/ disk, causing plastic deformation of the disk and rapid temperature rise resulting in failure of the contact interface, There are problems such as data loss and so on. In this way, the contact behavior of magnetic head and magnetic disk has become one of the most important reasons for data loss of current and future magnetic storage devices. However, it is difficult to provide technical support for magnetic head/ disk contact demagnetization. In this paper, the magnetic behavior of magnetic head/ disk contact is studied by using micro-magnetic simulation method, finite element method and experimental method, which covers the following aspects: based on the influence of plastic deformation on the magnetic domain, this paper starts from the two aspects of dislocation pinning and residual stress. Magnetic plastic energy and magnetic stress energy can be calculated by using domain wall pinning model and inverse magnetic resonance principle. In addition, the characteristics of vector characteristics, tensile properties and film thickness are added into the magnetoplastic energy. Thus, based on these two energy formulas, a magnetic plastic model based on micro-magnetic theory is established. In addition, two methods of solving the magnetic plastic model based on the micro-magnetic theory are also put forward, and the construction of the magnetic plastic model is perfected. In this paper, the magnetic behavior of magnetic head/ disk contact is simulated by nano scratch test, and a quantitative detection method is proposed by using the principle of phase imaging of magnetic microscope, thus defining the critical demagnetization condition of magnetic disk and the contact force of magnetic head/ disk. The damage degree of the disk surface and the influence of the number of repeated strokes of the head/ disk on the magnetic change of the magnetic disk. Subsequently, based on the magnetic head/ magnetic disk sliding contact finite element model and the magnetic plastic model, the process of magnetic disk magnetization due to the magnetic behavior of the magnetic head/ disk can not be obtained. Moreover, the correctness of the constructed magnetic plasticity model is verified by the comparison and analysis of magnetic characteristics of magnetic disk media and simulation results. By combining the random thermal perturbation term, Voronoi model characteristic and the magnetic plastic model, a Voronoi micro-magnetic simulation model involving thermal coupling is established, and the plastic strain/ elastic stress under the influence of temperature is obtained. the dependence of the directivity and the tensile force and the magnetization of the perpendicular magnetic recording medium. in turn, a finite element model of high speed sliding contact of a magnetic head/ disk is established, and the influence of magnetic moment deflection change on the attenuation of the magnetic information during the magnetic head/ disk contact demagnetization process is further disclosed, and the contact force of the magnetic head/ disk is obtained, The effect of scratch speed on the SNR of the medium associated with the transition noise. Finally, using the collision experiment of stainless steel ball and magnetic disk, the correctness of the finite element model of high speed sliding contact of magnetic head/ disk and Voronoi micro-magnetic simulation model is determined. Under the action of magnetic head/ disk contact, this paper obtains the influence law of anti-contact demagnetization performance of magnetic disk media by changing the material thermodynamics properties of magnetic disk media, the magnetic properties of magnetic disk media and the magnetic properties of materials and the interface parameters of magnetic head/ disk contact. thereby realizing the purpose of improving the high temperature resistance, the high stress response ability of the magnetic recording layer or keeping the good recording state of the magnetic recording layer. It is pointed out that this paper also gives consideration to the problem of preventing the contact demagnetization of magnetic disk media. "Three Difficult Position" a solution to the problem.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP333.3
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1 刘育良;磁盘力磁特性和热力耦合作用下接触退磁行为研究[D];哈尔滨工业大学;2016年
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