在超性接触中的摩擦的正负调节系数
Zhanghui Wu1,2, Xuanhe Li1,3, Deli Peng1,2,4
1Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
Physical review letters
|April 29, 2024
概括
石墨和矿表面之间的摩擦显示出独特的钟形曲线,随着负载增加,由于边缘脱落而减少. 这一发现为调整超滑应用中的摩擦系数 (COF) 提供了新的途径.
科学领域:
- 部落学 (tribology) 是一个学科.
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
背景情况:
- 传统的摩擦系统具有正的摩擦系数 (COF),表明摩擦与正常力增加.
- 超滑接触,特别是那些涉及石墨等多层材料的接触,具有独特的摩擦行为.
- 了解负载依赖对于优化高级应用程序中的 tribological 性能至关重要.
研究的目的:
- 为了研究石墨和α- (α-Al_{2}O_{3}) 表面之间的摩擦的负载依赖.
- 为了阐明对观察到的摩擦行为负责的潜在机制.
- 探索在超性接触中调COF的潜力.
主要方法:
- 在不同的正常力下测试摩擦特性.
- 有限元模拟用于模拟界面力学.
- 经验验证通过改变尖端曲率和石墨片的厚度来验证.
主要成果:
- 观察到一个独特的钟形摩擦负载依赖曲线.
- 摩擦最初会随着正常力增加,然后减少.
- 有限元模拟确定了在石墨/α-Al_{2}O_{3}接口上的边缘脱落是原因.
结论:
- 超滑接触器的边缘脱离显著减少了整体摩擦.
- 这项研究提出了一种新的机制,以实现可调节的,可能是负的COF值.
- 这些发现为设计低摩擦和可控制的部落系统的新策略铺平了道路.
相关概念视频
Frictional Force
7.9K
When a body is in motion, it encounters resistance because the body interacts with its surroundings. This resistance is known as friction, a common yet complex force whose behavior is still not completely understood. Friction opposes relative motion between systems in contact, but also allows us to move. Friction arises in part due to the roughness of surfaces in contact. For one object to move along a surface, it must rise to where the peaks of the surface can skip along the bottom of the...
7.9K
Kinetic Friction
923
Consider a truck trying to pull a stationary car. As the truck exerts a force on the car, static friction is created at the point of contact between the two surfaces. This frictional force resists the car's movement and keeps it at rest. However, when the applied force by the truck surpasses the limiting static frictional force, an interesting phenomenon occurs. The frictional force at the interface reduces to a lower value, known as the kinetic frictional force. At this point, the car...
923
Characteristics of Dry Friction
559
Dry friction occurs when two solid surfaces slide against each other without any lubrication or fluid present. It causes resistance when pushing objects along a surface, like a gardener pushing a wheelbarrow. The force applied to move the cart causes dry friction between the wheel and the ground.
Before the wheelbarrow starts moving, the static frictional force acts tangentially to the contact surface, opposing the force that is about to induce the motion. This frictional force prevents the...
Before the wheelbarrow starts moving, the static frictional force acts tangentially to the contact surface, opposing the force that is about to induce the motion. This frictional force prevents the...
559
Types of Friction Problems
531
Friction is an essential concept in physics, engineering, and everyday life. It is the force that opposes the relative motion or tendency of such motion between two surfaces in contact. One of the most common types of friction encountered in various applications is dry friction. Dry friction problems can be broadly categorized into three types, each with unique characteristics and challenges.
The first type of dry friction problem involves situations where there is no apparent impending motion....
The first type of dry friction problem involves situations where there is no apparent impending motion....
531
Static Friction
759
Static friction is a force that opposes the relative motion or tendency of motion between two surfaces in contact. It plays a crucial role in our daily lives, from walking on the ground to driving a car.
For example, consider a scenario where a truck is connected to a car by a rope, ready to tow it along a road. When no external force is applied by the truck, the car remains stationary and is said to be in static equilibrium. In this case, the forces acting on the car, such as gravity and the...
For example, consider a scenario where a truck is connected to a car by a rope, ready to tow it along a road. When no external force is applied by the truck, the car remains stationary and is said to be in static equilibrium. In this case, the forces acting on the car, such as gravity and the...
759
Dry Friction
384
Dry friction occurs between two solid surfaces in contact as they attempt to move relative to one another. In daily life, dry friction is encountered in various forms, such as when walking on the ground, sliding an object across a table, or rubbing hands together. Despite its ubiquity, the underlying mechanisms behind dry friction are not readily visible.
To illustrate this concept, imagine a wooden crate resting on a rough, non-uniform horizontal surface. When an external force is applied to...
To illustrate this concept, imagine a wooden crate resting on a rough, non-uniform horizontal surface. When an external force is applied to...
384


