Friction control by means of self-assembled nano-lubricant film

研究的目的是了解HDI的摩擦学现象，特别是当磁头飞行高度小于10 nm时。本文主要研究磁盘表面超薄润滑膜的摩擦学特性和纳米润滑膜的优化设计。润滑剂膜必须具有粘附性（对固体表面）和流体特性，因此良好的润滑剂膜由合适的粘合层和移动的层组成。本论文的主要目的是研制一种具有低摩擦、高耐久性和高振动稳定性的双单层润滑膜的润滑系统。1.在无定形碳表面气相沉积强键碳氢化合物膜本文介绍了用真空气相沉积法在碳表面沉积强键碳氢化合物膜（癸醇和癸酸）。从接触角测试和X射线光电子能谱测量的结果，我们认为， ...更多信息 因为具有羟基或羧基端基的烃分子可以通过气相沉积牢固地键合在碳表面上。它与碳表面上的羟基或羧基端基与不饱和电子之间的静电相互作用有关。PFPE润滑膜的自憎性对磨损性能的影响在实际HDD中产生近接触或接触滑块的情况下，PFPE薄膜的作用变得更加重要。已知具有固定在固体表面上的OH或COOH末端的PFPE的单层膜表现出自憎性，并且PFPE单层上的PFPE分子粘附并形成液滴。对PFPE纳米润滑膜的稳定性进行了研究，结果表明，去湿后的表面表现出较高的摩擦系数和较低的使用寿命。3声发射法观察磨损过程阐明了粘结层和移动的层的摩擦特性，并提出了它们作为HD润滑剂的理想组合。它还表明，PFPE纳米润滑剂膜的寿命是强烈的结合和移动的层厚度的组合的影响。除此之外，我们澄清了PFPE纳米润滑膜与小玻璃球滑动的摩擦痕迹，使用销-盘摩擦试验机或旋转架配置反映了移动的层的磨损，然后是粘结层的磨损。我们现在专注于分析纳米润滑油膜的磨损过程中使用AE测量使用AE传感器固定在玻璃球。它是澄清的粘结和移动的膜的磨损过程可以区分由测量的AE数据的精心处理。声发射测量结果进一步阐明了粘结层和移动的层的作用，强调了二者结合的重要性。少

The objective of the research is to understand the tribological phenomenon of HDI, particularly when the head flying height is smaller than 10 nm. The clarification of tribological characteristics of an ultra thin lubricant film on the magnetic disk and the optimum design of the lubricant nanofilm are focused on in this research. Lubricant film must have both adhesive (to solid surface) and fluidic characteristics thus a good lubricant film consists of suitable bonded and mobile layers. The development of ultimate lubrication system is aimed, which is made of bi-monolayer-lubricant film keeping low friction, high durability and high stability against vibration.1.Vapor deposition of strongly bonded hydrocarbon films on amorphous carbon surfacesIt is described that a deposition of strongly bonded hydrocarbon films (1-decanol and decanoic acid) on carbon surfaces by vacuum vapor deposition. From the results of contact angle tests and X-ray photoelectron spectroscopy measurements, we concl … More ude that the hydrocarbon molecules having hydroxyl or carboxyl end groups can be strongly bonded on carbon surfaces by vapor deposition. It is related to the electrostatic interaction between hydroxyl or carboxyl end groups and unsaturated electrons on carbon surfaces. The results of friction measurements are also discussed.2 An effect of autophobicity of PFPE lubricant film on wear propertyThe role of PFPE thin film becomes more important in case that near contact or contact slider is brought about in the actual HDD. It is known that a monolayer film of PFPE with OH or COOH ends fixed on a solid surface exhibits autophobicity and PFPE molecules on the PFPE monolayer cohere and make droplets. The stability of PFPE nano lubricant film is investigated and it is shown that the dewetted surface shows undeairable tribological characteristics such as higher friction and lower lifetime. It is also shown that the observation by microscope shows the droplets of PFPE molecules grows with time.3 Wear process observed by AE methodWe have clarified the frictional characteristics of bonded and mobile layers and proposed their desirable combination as HD lubricants. It was also shown that the lifetime of the PFPE nanolubricant film is strongly affected by the combination of bonded and mobile layer thicknesses. In addition to them we clarified that the frictional trace of PFPE nano lubricant film slid by a small glass ball using pin-on-disk tribotester or spin-stand configurations reflects the wear of mobile layer followed by the wear of bonded layer. We are now focusing on the analysis of the wear process of nanolubricant film using AE measurement using an AE sensor fixed on the glass ball. It is clarified that the wear process of the bonded and mobile films can be distinguished by an elaborate processing of the measured AE data. The results obtained by the AE measurements clarified more the roles of the bonded and mobile layers and emphasize the importance of the combination of them. Less