Determination of elastic moduli of elastic–plastic microspherical materials using nanoindentation simulation without mechanical polishing

Beilstein Journal of Nanotechnology

article

Hongzhou Li¹  Jialian Chen¹ 

[1] College of Environmental Science and Engineering, Engineering Research Center of Polymer Resources Green Recycling of Ministry of Education, Fujian Normal University

关键词: elastic–plastic;    microsphere;    nanoindentation;    Oliver–Pharr method;    simulation;   

DOI  :  10.3762/bjnano.12.17

学科分类：环境监测和分析

来源: Beilstein - Institut zur Foerderung der Chemischen Wissenschaften

【 摘 要 】

When using the Oliver–Pharr method, the indented specimen is assumed to be a perfectly flat surface, thus ignoring the influencesof surface roughness that might be encountered in experiment. For nanoindentation measurements, a flat surface is fabricated fromcurved specimens by mechanical polishing. However, the position of the polished curved surface cannot be controlled. There are noreliable theoretical or experimental methods to evaluate the mechanical behavior during nanoindentation of an elastic–plasticmicrosphere. Therefore, it is necessary to conduct reliable numerical simulations to evaluate this behavior. This article reports asystematic computational study regarding the instrumented nanoindentation of elastic–plastic microspherical materials. The ratiobetween elastic modulus of the microsphere and the initial yield stress of the microsphere was systematically varied from 10 to1000 to cover the mechanical properties of most materials encountered in engineering. The simulated results indicate that contactheight is unsuitable to replace contact depth for obtaining the indentation elastic modulus of microspherical materials. The extractedelastic modulus of a microsphere using the Oliver–Pharr method with the simulated unloading curve depends on the indentationdepth. It demonstrates that nanoindentation on microspherical materials exhibits a “size effect”.

【 授权许可】

CC BY