Phase Equilibria and Atomic Diffusion in the Ir/CoAl System
Aiming for the design of simple thermal coatings including Ir as a diffusion barrier layer with B2 aluminides bond coat such as CoAl, diffusion behavior and phase equilibria at the Ir/CoAl interface have been investigated to understand thermal and chemical stability of the interface. Diffusion couples were prepared with various conditions of Ir, plate, powder and film deposited to examine the effects on diffusion behavior. Moreover, the interdiffusion coefficient of binary Ir-M in the Ir solid solution, DIr-M was determined using Boltzmann-Matano method, where M is selected form elements used in heat resistant alloys. The potential of Ir as a diffusion barrier has been evaluated particularly against diffusion of Al.
Young Won Chang, Nack J. Kim and Chong Soo Lee
Y. Kimura et al., "Phase Equilibria and Atomic Diffusion in the Ir/CoAl System", Materials Science Forum, Vols. 561-565, pp. 477-480, 2007