Weakening effect of plastic yielding inception in thin hard coating systems
Xiao Huang(黄啸)1, Shujun Zhou(周述军)1, and Tianmin Shao(邵天敏)2,†
1 School of Mechanical Electronic and Information Engineering, China University of Mining and Technology, Beijing 100083, China; 2 State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
Abstract Hard coatings have been widely applied to enhance tribological performance of mechanical components. However, it was predicted that thin hard coatings may have a weakening effect which could reduce the coating/substrate system's resistance to plastic yielding compared with the uncoated substrate material. In this paper, analytical simulation is utilized to investigate the origin of weakening effect. The functions of material mechanical properties and coating thickness on the weakening effect are theoretically investigated. Partial-unloading spherical nanoindentation tests are performed on tungsten coated single crystalline silicon and copper to acquire the stress-strain curves and compared with the uncoated cases. The experimental results are in consistence with the analytical solutions, demonstrating the presence of weakening effect.
Fund: Project supported by the National Natural Science Foundation of China (Grant No. 51705533), the National Science and Technology Major Project of China (Grant No. 2017-VII-0013-0110), the Fundamental Research Funds for the Central Universities, China (Grant No. 2020YQJD17), and the Tribology Science Fund of State Key Laboratory of Tribology (Grant No. SKLTKF18B15).
Xiao Huang(黄啸), Shujun Zhou(周述军), and Tianmin Shao(邵天敏) Weakening effect of plastic yielding inception in thin hard coating systems 2021 Chin. Phys. B 30 038104
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