Phase transformation is an important factor in designing and application of Titanium alloys. The phase stability, lattice dynamics and martensitic phase transformation in Ti-based Ti-V b.c.c. alloys are studied using Embedded Atom Method (EAM), Quasi-harmonic Approximation and Molecular Dynamics (MD) calculations. The model predictions are tested with respect to the relative thermodynamic stability of phases as a function of temperature and the alloy composition, and with respect to the phone dispersion curves and the phonon density of states. The predict effect of V on two phonon modes, a T1 N-point 1/2[110] phonon and T1 [112] phonon, which play the key roles in the b.c.c.to h.c.p. transformation, was found to be consistent with experiment.
The EAM-based total energy calculation showed, and the MD simulation results confirmed, that the actual b.c.c. to h.c.p. transformation path involves a simultaneous operation of the {110}<-110> shuffling and the {112}<11-1> shear processes, and the transformation is initially dominated by the shuffling. The addition of V stabilizes the b.c.c. structure.
1. P. Dang and M. Grujicic, "A study of Crystal Defects Effect on the Martensitic Transformation in Ti-V B.C.C. Beta Alloy", Modeling and Simulation in Materials Science and Engineering , 123-136, 4 (1996).
2. M. Grujicic and P. Dang, "Atomic-Scale Analysis of Martensitic Transformation in Titanium Alloyed with Vanadium -- Part I: Verification of the EAM Model", Materials Science and Engineering A, 139-152, 205 (1996).
3. M. Grujicic and P. Dang, "Atomic-Scale Analysis of Martensitic Transformation in Titanium Alloyed with Vanadium -- Part II: Molecular Dynamics Study", Materials Science and Engineering A, 153-165, 205 (1996).
4.M. Grujicic and P. Dang, "Computer Simulation of Martensitic Transformation in Fe- Ni Face-Centered Cubic Alloys", Materials Science and Engineering A, 194-204, 201 (1995).
5. M. Grujicic and P. Dang, "Assessment of Thermodynamic Properties of Alloys by Combining the Embedded-Atom and the Quasi-harmonic Method", Calphad, 105-117, 19 (1995).
Back to Ping Dang's Home Page