Effects of Ni3Ti (DO24) Precipitates and composition on Ni-based superalloys using molecular dynamics method

• Main Author: Goh, Kian Heng
• Format: Thesis
• Language: English
• Published: 2013
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.utm.my/id/eprint/39006/5/GohKianHengMFKM2013.pdf; http://eprints.utm.my/id/eprint/39006/
• Institution: Universiti Teknologi Malaysia

The main aim of this study is to simulate and investigate the gamma and gamma prime phases structure stability and behaviour of misfit dislocation-precipitate with additional of Ni3Ti (DO24) in Ni-based superalloys using MD at 10 K, 293 K and 1000 K. The Ni3Ti are homogeneously distributed through ? phase and the percentages are varied from 0.22%, 0.5%, 0.89% and 2.11%. MD is capable to produce three dimensions modelling based on time evolution of a set of interacting atoms and integrating their equation of motion. The Embedded Atom Method (EAM) is used to calculate phase stability, point defect properties, surface energies and relaxation for Ni-Ti-Al system. The empirical embedding energy function, electron density function and interatomic pair potential function used by this method are obtained. The conclusion of this simulation shows that distribution of Ni3Ti is vital in determining the Ni-Ni3Al phase stability. The data of temperature, total energy, stress in x-axis, stress in y-axis, stress in z-axis and volume are plotted and snapshot of each percentage of Ni3Ti added is taken at different step. At higher temperature (1000 K), it is more favourable and stable condition for higher Ti concentration (9L 2.11%) because of lower energy level and more stable temperature condition.