Dynamics of Atomic Stick-Slip Friction

原子粘滑摩擦动力学

• 批准号: RGPIN-2014-04748
• 负责人: Egberts, Philip
• 金额: $ 1.82万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649944
• 关键词: Dynamics; Atomic; Stick; Slip; Friction

The objective of this project is to gain further understanding of the dynamic aspects of frictional sliding at the atomic scale. In particular, this project will be focused on examining the structure of extremely small, nanoscale sliding contacts, characterizing the thermal and mechanical fluctuations of the contact under static and sliding conditions, and the effect thermal energy has on reducing friction in dry lubricated contacts. Examination of such fundamental concepts is crucial, despite the fact that the concept of friction is considered relatively simple. For example, although it is possible to easily measure friction and catalogue its effects, there currently exists no method of predicting the friction behaviour that will occur when two materials are brought into contact and begin to slide against each other. While our existing empirical friction laws have been widely exploited to date, innovation in the field of tribology, or the field concerned with understanding friction, is critical for improved environmental performance of mechanical systems, enhanced durability of these systems, and technological innovation of micro-/nano-electromechanical (M/NEMS). Given the goal of producing machines that are extremely energy efficient, long-lasting, and have low maintenance needs, an improved understanding of friction, with a specific emphasis of reducing the problem to physically predictive values and theories, is required. Nanotechnology and nanoscience are often thought of enabling these goals, as the complex problem of friction can be reduced in complexity to one that can be experimentally measured as well as completely re-created within a computer simulation.**In this research program, atomic force microscopy (AFM) will be used to examine friction between small, nanometre-sized tips sliding on a surface of atomically flat solid lubricants. AFM will be used in this study because it is able to measure forces sufficiently small to detect single chemical bonds breaking events, as well as laterally slide the tip along the surface by atomic distances. One issue with measuring friction with an AFM is that typical sliding speeds that can be achieved are on the order of 100 nm/s while typical machines operate at m/s sliding speeds. Measures will be taken to correct this deficiency in experiments. Furthermore, the influence of mechanical vibrations on reducing friction will be examined and their contributions to velocity dependent friction will be analyzed. This fundamental research represents the groundwork for reaching predictive models of friction, and will have far reaching impact on science and technology both in research institutions and industry.

该项目的目的是进一步了解原子量表的摩擦滑动的动态方面。 特别是，该项目将集中于检查极小的纳米级滑动触点的结构，以表征在静态和滑动条件下接触的热和机械波动，并且热能对减少干润滑接触中摩擦的影响具有效果。 尽管摩擦的概念被认为相对简单，但对这种基本概念的检查至关重要。 例如，尽管可以轻松测量摩擦和对其效应进行分类，但目前尚无预测当两种材料接触并开始相互互动时会发生的摩擦行为的方法。 尽管我们现有的经验摩擦法律已被广泛利用，但摩擦学领域或与理解摩擦有关的领域的创新对于改善机械系统的环境性能，这些系统的耐用性提高以及微型技术创新至关重要。 /纳米电力力学（m/nems）。 考虑到生产极有节能，持久且维护需求较低的机器，对摩擦的理解得到了改善，并且需要具体的重点将问题减少到物理预测的价值和理论。 纳米技术和纳米科学经常被认为可以实现这些目标，因为可以将复杂的复杂问题降低到可以在计算机模拟中进行实验测量并完全重新创建的摩擦。显微镜（AFM）将用于检查在原子固定固体润滑剂表面上滑动的小纳米大小的尖端之间的摩擦。 本研究将使用AFM，因为它能够测量足够小的力来检测单个化学键破坏事件，并通过原子距离横向滑动尖端。 用AFM测量摩擦的一个问题是，可以实现的典型滑动速度在100 nm/s的订单上，而典型的机器则以m/s的滑动速度运行。 将采取措施来纠正实验中的这种不足。 此外，将检查机械振动对减少摩擦的影响，并将分析它们对速度依赖性摩擦的贡献。 这项基本研究代表了达到摩擦预测模型的基础，并将对研究机构和行业的科学技术产生巨大影响。