Effect of cyrstal orientation on tensile mechanical properties
Soh, Jerome Wei Jie
Date of Issue2016
School of Mechanical and Aerospace Engineering
The tensile mechanical properties of single-crystal face-centered cubic (FCC) aluminium (Al) are investigated via molecular dynamics (MD) simulation. Al is one of the largely used materials due to its good mechanical properties. The studies of Al have intensified interest towards new-Al based nanomaterials which have resulted in the production of new nanodevices that have smaller length scales and enhanced functionalities. However, the reduced length scales have led to challenges in material strength properties and thus, there is a demand for greater understanding of the tensile mechanical properties for such nanoscale materials and structures. Mechanical properties at the nanoscale have shown novel features that have yet to be captured in the macroscale. Moreover, the mechanical and physical properties of Al-based nanomaterials are highly dependent on its atomic structure, as it is often affected by strain, chemical functionalization and presence of structural interruptions during their application. Hence, this project aims to study and comprehend the effects of the crystallographic orientation, notch and temperature on the tensile mechanical properties of single-crystal Al via MD simulation. Firstly, the tensile mechanical properties of single-crystal Al is investigated when subjected to different crystal orientations. Tensile loading in the ,<100>, <110> and <111> directions is applied to the different single-crystal Al and it is found that the <100> tend to be the strongest orientation out of the 3 observed crystal orientations with <111> being the weakest. Secondly, the effect on the tensile mechanical properties of single-crystal Al is studied when a notch is added to the specimen. In general, the results have shown that the addition of the notch adversely affects the tensile mechanical properties. Lastly, the temperature effect is also considered and it is found that the increase in temperature on the material also has an adverse result on the tensile mechanical properties. Therefore, the findings made in this project have increased the understanding of the effects of the crystal orientations on the tensile mechanical properties of the single-crystal Al. This knowledge not only helps to ensure stronger Al-based nanodevices but it also ensures that they function optimally with minimum failure. As such, more progress can be achieved in their functionality enhancements and their applications.
Final Year Project (FYP)
Nanyang Technological University