MAEAM investigation of the structural stability and theoretical strength of Fe crystals under uniaxial loading
✍ Scribed by Jian-Min Zhang; Jing-Zhou Wang; Ke-Wei Xu
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 790 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0232-1300
No coin nor oath required. For personal study only.
✦ Synopsis
The structural stability and theoretical strength of BCC crystal Fe under uniaxial loading have been investigated with the modified analytic embedded-atom method (MAEAM). Even if an orthorhombic path is applied, the deformation is spontaneous along the tetragonal path till Milstein modified Born criterion B 22 -B 23 >0 is violated at λ 1 =0.9064 in the compressive region. The branched orthogonal path with lower compressive stress σ 1 and energy E is preferred over the conventional tetragonal Bain path. A stress-free FCC phase with the local maximum energy of -4.2186eV appearing either in compressive region (orthorhombic path) at λ 1 =0.8923 or in tensile region (tetragonal path) at λ 1 =1.2619 is unstable and would slip spontaneously into its near neighbor stress-free mBCT phase with the local minimum energy of -4.2270eV. The initial BCC phase with the lowest energy of -4.280eV is the most stable in correspondence with the actual behavior of Fe. Furthermore, the stable region ranges from -79.7eV/nm 3 to 30.6eV/nm 3 in the theoretical strength or from 0.9064 to 1.1788 in the stretch λ 1 correspondingly.