Effect of Pt on diffusion-controlled growth characteristics of interdiffusion zone between CM247LC superalloy and Ni(Pt)Al bond coat

Diffusion-controlled growth of interdiffusion zone between CM247LC directionally solidified superalloy and platinum-containing nickel aluminide bond coat is studied. The growth mechanism of the interdiffusion zone is explained to describe two different parts: precipitate-free and precipitate containing interdiffusion zone. Pt and Al content strongly influence the compositional distribution, growth of phases, and growth kinetics. However, the types of topologically close-packed phases are the same irrespective of the difference in bond coat composition. In-depth TEM analysis indicates the presence of µ , σ , P , and R phases. The compositions of certain components in these phases are found to be significantly different. Graphical abstract