No abstract

When a material is immersed in a low-temperature medium, e.g., liquid nitrogen, its Young’s modulus and surface roughness will change as the temperature of the material decreases as a result of different friction behaviors. In this study, a high-precision friction test device was constructed to perform a detailed comparative study on the friction properties of a pure copper strand immersed in liquid nitrogen, air, and water. The force and displacement resolutions of the experimental system were as high as 0.01mN and 0.03μm, respectively. It was found that the stick-slip phenomenon in the liquid nitrogen was significant, while the slope of the stick-slip was larger than those observed in the air and water media. These experimental results were simulated using a spring-slider model that considered the influence of hydrophilicity on surface roughness. The roughness was shown to change the amplitude of the friction curve with time, while the slope of the stick-slip was dominated by the modulus’ magnitude variety.

Electrical-field-induced magnetic Skyrmion ground state in a two-dimensional chromium tri-iodide ferromagnetic monolayer AIP Advances 8, 055316 (2018)

The presented self-developed high-precision contact friction test device conducts experimental research on the friction characteristics of concrete pavement. First, the error analysis of the test device is carried out. The structure shows that the test device meets the test requirements. Subsequently, the device was used to carry out experimental research on the friction performance of concrete pavement under different roughness and temperature changes. The results showed that the friction performance of concrete pavement increased with the increase in surface roughness, and decreased with the increase in temperature. It has a small volume and significant stick-slip properties. Finally, the spring slider model is used to simulate the friction characteristics of the concrete pavement, then the shear modulus and viscous force of the concrete material are adjusted to achieve the calculation of the friction force over time under temperature changes, which is consistent with the experimental structure.