The kinetics of diffusional phase transformations in the pseudobinary Ni3Al-Ni3V system were studied using a computer simulation technique based on microscope diffusion equations. Our focus is on the initial stages of atomic ordering and compositional clustering process during the phase transformation of an initially homogeneous disordered f.c.c. ternary alloy (Ni75Al25 - xVx) into a two-phase mixture of L12 (Ni3Al) and DO22 (Ni3V) ordered phases. A thermodynamic model is proposed to describe the phase equilibria in this pseudobinary system. Our computer simulations demonstrated that at small vanadium content, the L12 ordered domains appear first, followed by the nucleation of DO22 ordered domains at the antiphase domain boundaries of L12, whereas at large vanadium content, precipitation of DO22 precedes L12 domain formation. The simulation results are discussed employing the thermodynamic stability analysis. The ordering and clustering kinetics predicted from our computer simulation are consistent with recent experimental observations.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys