Interdiffusion behavior in sigma-phase using Ni3Al/Mo diffusion couples

The sigmaNiMo( Al) phase was formed using Ni3Al/Mo diffusion couples at 1423, 1473 and 1523 K. The growth of formed phase and the concentration-distance profiles for each component in the diffusion couples were examined by electron probe microanalysis (EPMA). The activation energy for the parabolic growth of ? phase is found to be 525.3 kJ/mol. The concentration dependence and average ternary interdiffusion coefficients in single ?-NiMo(Al) phase were calculated, and the Arrhenius equations of the D for the ?-NiMo(Al) phase are calculated, the diffusional interaction between Ni, Mo and Al in ?-NiMo(Al) phase was studied by the crossinterdiffusion coefficients. Moreover, these results were utilized to explain the ? phase formation and growth in ?? phase.

Modeling of Coarsening Processes In Patterned Systems

ABSTRACTAlthough particle coarsening has been studied for over a century, it remains an active area of materials science research. The current work presents a theoretical analysis of the degradation of regular arrays of spherical particles through diffusional interaction. In order to understand the onset of coarsening, a linear stability analysis is performed on a simple square lattice of particles. It is predicted that particles will dissolve in a spatially ordered manner. The active transport mechanism plays a strong role in the selection of the coherent growth modes.