Study of Structure and Deformation Pathways in Ti-7Al Using Atomistic Simulations,Experiments, and Characterization |
| |
Authors: | Ajey Venkataraman Paul A Shade R Adebisi S Sathish Adam L Pilchak G Babu Viswanathan Matt C Brandes Michael J Mills Michael D Sangid |
| |
Affiliation: | 1.School of Aeronautics and Astronautics,Purdue University,West Lafayette,USA;2.Materials and Manufacturing Directorate, AFRL/RXCM, Air Force Research Laboratory,Wright-Patterson AFB,USA;3.University of Dayton Research Institute,Dayton,USA;4.Department of Materials Science and Engineering,The Ohio State University,Columbus,USA |
| |
Abstract: | Ti-7Al is a good model material for mimicking the α phase response of near-α and α+β phases of many widely used titanium-based engineering alloys, including Ti-6Al-4V. In this study, three model structures of Ti-7Al are investigated using atomistic simulations by varying the Ti and Al atom positions within the crystalline lattice. These atomic arrangements are based on transmission electron microscopy observations of short-range order. The elastic constants of the three model structures considered are calculated using molecular dynamics simulations. Resonant ultrasound spectroscopy experiments are conducted to obtain the elastic constants at room temperature and a good agreement is found between the simulation and experimental results, providing confidence that the model structures are reasonable. Additionally, energy barriers for crystalline slip are established for these structures by means of calculating the γ-surfaces for different slip systems. Finally, the positions of Al atoms in regards to solid solution strengthening are studied using density functional theory simulations, which demonstrate a higher energy barrier for slip when the Al solute atom is closer to (or at) the fault plane. These results provide quantitative insights into the deformation mechanisms of this alloy. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|