Interdiffusion in the Pt/ β-NiAl System

摘要

Interdiffusion in Pt/β-NiAl diffusion couples at 1073-1273 K temperature range was investigated. Using the Inverse Method and the Generalized Darken's Method the intrinsic diffusivities of platinum, nickel and aluminium in the Pt-Ni-AI system have been calculated allowing the estimation of the activation energies and pre-exponential factors for Pt, Ni and Al diffusion have been obtained. In a whole range of temperatures at 1073-1273 K the intrinsic diffusivity of the aluminium is approximately one order of magnitude higher that the apparent diffusivities of nickel and platinum. These results confirm the earlier assumption that enhanced diffusion of aluminium is a limiting factor in conferring very good corrosion resistant properties to platinum-aluminide coatings on nickel base superalloys.