Speaker
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Abstract content <br> (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>
Shape memory alloys (SMAs) exhibits two unique properties namely the shape memory effect and superelastisity which occur as a results of face transformation. These properties enable the metals to remember their previous shape after being deformed when heated above certain temperatures. The effect of ternary addition Zr on B2 TiPt SMAs has been investigated using density functional theory. The supercell approach embedded in VASP code was used to partially substitute Ti with Zr atom on the cubic TiPt to form TiPt(Zr). Their structural, mechanical properties and temperature dependence have been calculated. It was found that the shear modulus for Zr6.25Ti 43.75Pt50 and Zr18.25Ti31.25Pt 50 is negative suggesting mechanical instability, while a positive shear modulus is observed for Zr25Ti25Pt50 (mechanical stability). The phonon dispersions for the Zr6.25Ti43.75Pt50, Zr18.25Ti31.25Pt50 and Zr25Ti25Pt50 shape memory alloys were calculated and the phonon dispersion curves revealed a softening of modes along high symmetry directions M, R and Γ. This is due to C44 being > C', which corresponds to branches in the negative direction. Furthermore, LAMMPS code was used to determine the lattice expansion of the Ti50-xPt50Zrx ternaries at various temperature range. It was observed that as Zr content is increased with increased temperature, the structure remains cubic below 900K. However, at temperature above 900K, the lattice parameter are different (a≠b≠c) suggesting a possible transformation from a cubic to triclinic phase.
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
MSc
Main supervisor (name and email)<br>and his / her institution
Prof. HR Chauke
hr.chauke@ul.ac.za
University of Limpopo
Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)
No