Multiscale analysis of friction behavior at fretting interfaces

Zhinan Zhang,Shuaihang Pan,Bin Shen,Nian Yin,Jie Song

doi:10.1007/s40544-019-0341-z

Zhinan Zhang, Shuaihang Pan + Show 3 more

Open Access

https://doi.org/10.1007/s40544-019-0341-z

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Abstract

Friction behavior at fretting interfaces is of fundamental interest in tribology and is important in material applications. However, friction has contact intervals, which can accurately determine the friction characteristics of a material; however, this has not been thoroughly investigated. Moreover, the fretting process with regard to different interfacial configurations have also not been systematically evaluated. To bridge these research gaps, molecular dynamics (MD) simulations on Al-Al, diamond-diamond, and diamond-silicon fretting interfaces were performed while considering bidirectional forces. This paper also proposes new energy theories, bonding principles, nanoscale friction laws, and wear rate analyses. With these models, semi-quantitative analyses of coefficient of friction (CoF) were made and simulation outcomes were examined. The results show that the differences in the hardness, stiffness modulus, and the material configuration have a considerable influence on the fretting process. This can potentially lead to the force generated during friction contact intervals along with changes in the CoF. The effect of surface separation can be of great significance in predicting the fretting process, selecting the material, and for optimization.

Highlights

Crystalline materials, such as metallic crystals and atomic crystals, can have a broad niche of applications for their distinctive properties
The friction and the normal force to friction were treated as relative values to describe the changes during the fretting processes as presented in Figs. 1(a) and 1(b) [43]
The first friction contact process was investigated for severe wear or deformation, which is presented Fig. 3

Summary

Introduction

Crystalline materials, such as metallic crystals and atomic crystals, can have a broad niche of applications for their distinctive properties. Aluminum (Al) is a typical and important metallic crystal that is often used as the base material in many essential parts in spacecraft [1,2,3,4], automobiles, and electronics such as batteries and triboelectric nanogenerators [5, 6]. This can be attributed to the high performance, good utility, and relatively low cost of aluminum. These materials, owing to their small-scale surface roughness (1–1,000 nm), inevitably suffer from micro-scale motions, i.e., the fretting process, when they form interfaces under normal service [9, 10]

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