Microstructural stability of fcc-gamma+B2-beta coatings on gamma substrate in Ni-Cr-Al system - A phase field model study
A two-dimensional phase field model was employed to examine the evolution of interdiffusion microstructures in ternary Ni-Cr-Al solid-to-solid diffusion couples containing fcc-gamma and gamma+beta (fcc+B2) alloys. Alloys of varying compositions and volume fractions of the second phase (beta) were examined to simulate the dissolution kinetics of the beta phase (i.e., recession of gamma+beta two-phase region) observed in gamma vs. gamma+beta diffusion couples. Simulation results showed that the rate of recession of gamma+beta two-phase region was dependent on the composition of the single-phase gamma alloy and the volume fraction of the beta phase in the two-phase alloy of the Couple. Specifically, the higher the Cr and Al content in the gamma alloy and the higher the volume fraction of beta in the gamma+beta alloy lower is the rate of dissolution. Although the volume fraction played a role, the concentration gradients of Al and Cr in the gamma phase (e.g., between the matrix of gamma+beta alloy and single-phase gamma alloy) also influenced the recession of the beta phase. Simulated results were found to be in good agreement with the experimental observations in ternary Ni-Cr-Al solid-to-solid diffusion couples containing gamma and gamma+beta alloys. (C) 2008 Elsevier B.V. All rights reserved.
Surface & Coatings Technology
"Microstructural stability of fcc-gamma+B2-beta coatings on gamma substrate in Ni-Cr-Al system - A phase field model study" (2008). Faculty Bibliography 2000s. 736.