单个粒子之间的滑动和滚动接触的特征
Simon Scherrer1, Shivaprakash N Ramakrishna1, Vincent Niggel1
1Department of Materials, ETH Zürich, Zürich 8093, Switzerland.
概括
悬浮中的颗粒接触是它们流动性质的关键. 这项研究揭示了粗性和粘附性如何微观地影响摩擦和粒子运动,为控制材料行为提供了新的方法.
科学领域:
- 类风病学 类风病学 类风病学
- 体科学是一种体科学.
- 部落学 (tribology) 是一个学科.
背景情况:
- 颗粒接触控制了密集,剪切悬浮的风学.
- 微观了解粗性和粘附性如何影响接触器中的力传递是有限的.
- 之前的研究缺乏直接实验测量粒子接触层上的摩擦系数.
研究的目的:
- 实验性地研究粒子接触时的力传递和相对运动的微观机制.
- 同时测量正常和触力,定制表面和微粒之间的滑动和滚动摩擦.
- 阐明表面粗度和粘附在决定粒子接触动态和质性质方面的作用.
主要方法:
- 开发和应用一种创新的合式探针原子力显微镜技术.
- 在粒子-表面相互作用期间同时测量正常和触力.
- 追踪相对滑动和滚动运动以确定摩擦系数.
主要成果:
- 当引力足够时,粒子自发滚动,减少能量消散,延长接触时间.
- 当滚动受到阻碍时,粗和粘合面的摩擦显著增加.
- 用聚合物刷的光滑颗粒表现出滑良好的接触,最大限度地减少摩擦.
- 表面粗性促进负载依赖的度相互锁定,诱导离轴粒子旋转和滚动.
- 光滑的粘合面导致沿主要运动轴滚动.
结论:
- 可以直接测量滑动和滚动摩擦系数.
- 了解表面特性如何影响粒子接触力学和质学的理解是先进的.
- 结果为数值模拟提供了关键数据,并为不连续剪切加厚提供了见解.
- 证明了通过工程表面接触量身定制悬浮体质学的潜力.
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