Grain size dependence of dissipation mechanisms in nanocrystalline aluminum using molecular dynamics simulationsOA
The effect of grain size(GS)on modulus and dissipation determines its impact on damping.This study uncovers the phenomenon of dissipation valleys in nanocrystalline metals through molecular dynamics simulations.The dynamic analysis of the microstructure reveals that the primary dissipation mechanism in the aluminum matrix shifts from being dominated by grain boundary sliding only to being jointly dominated by grain boundary sliding and grain diffusion.Specifically,at smaller GSs(e.g.,GS=10 nm),dissipation is primarily due to shear and thermal motion of atoms at grain boundaries,whereas larger GSs(e.g.,GS>10 nm)lead to an increase in diffusion of atoms from grain boundaries to the interior of grains.The competition between these two dissipation mechanisms results in the appearance of dissipation valleys.Subsequently,the effect of GS on damping and loss modulus of nanograined aluminum is further validated and precisely characterized by combining spectrum analysis and the use of a Maxwell viscoelastic model that takes into account both GB sliding and in tragran ular diffusion.This study establishes a mapping relationship between GS,microstructural deformation mechanisms,and dynamic energy dissipation,providing guidance for the design of nanocrystalline metals.
Fei Wang;Li Li;Xinli Jiang;Xuelin Wang;Yujin Hu
State Key Laboratory of Intelligent Manufacturing Equipment and Technology,School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China College of Mechanical Engineering,Taiyuan University of Technology,Taiyuan 030024,ChinaState Key Laboratory of Intelligent Manufacturing Equipment and Technology,School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,ChinaState Key Laboratory of Intelligent Manufacturing Equipment and Technology,School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,ChinaState Key Laboratory of Intelligent Manufacturing Equipment and Technology,School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,ChinaState Key Laboratory of Intelligent Manufacturing Equipment and Technology,School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China
通用工业技术
Damping capacityLoss modulusMolecular dynamicsNanograined metalGrain boundaryDiffusion
《Nano Materials Science》 2026 (4)
P.935-942,8
supported by the National Natural Science Foundation of China(No.52175095)the Key Research and Development Program of Guangxi of China(No.Guike AB23026106)the Young Topnotch Talent Cultivation Program of Hubei Province of China。
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