Yang, Jhen-yu

Amorphous Mg-Cu-Y metallic glasses are established by density functional theory and simulated annealing method in this study. The mechanical properties of amorphous Mg-Cu-Y metallic glasses are investigated by molecular statics simulations for the nano-indentation and the nano-scratch process.
In this study, some potential energy parameters are obtained by fitting for describing the Mg-Cu-Y system. The bulk modulus, the Young\ue2s modulus and X-ray structure of the Mg-Cu-Y system are calculated. Our results are within 10% error compared with experimental values, which prove the correctness of fitted potential parameters.
For the cases of nanoindentations, the indentation force-displacement and the influenced depth are calculated. The mechanical properties are obtained are close to experimental results. The both \ue2slip vector\ue2 and Honeycutt-Andemen index (HA index) parameters are also used to study the deformation behavior and bond-type of a group of atoms. Our results indicate that the influenced depths can be affected by the tip indentation and the gather of copper atoms. The gather of copper atoms can provide the resistance and strengthen the mechanical properties of Mg-Cu-Y material. On the other hand, our results indicate that the amorphous structure of Mg-Cu-Y metallic glasses cannot be transferred to crystal structure during nano-indentation process by analysis of HA index.
For the cases of nano-scratch, two different scratch depth (5&#x00C5; and 15&#x00C5;) are investigated to understand the understand the depth effect. the scratch force-displacement curve is also obtained. As the same with nano-indentation results, the scratch force will increase because the gather of copper atoms and provide the resistance

Molecular statics simulation of nano-indentation and nano-scratch on the amorphous Mg-Cu-Y metallic glasses

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