Thermal conductivity mapping of the Ni–Al system and the beta-NiAl phase in the Ni–Al–Cr system

We use two examples to highlight the power of micron-scale-resolution thermal conductivity mapping on graded compositions created in a diffusion-multiple sample in rapid establishment of composition–phase–property relationships. The Ni–NiAl diffusion couple example clearly shows the effects of solid solutioning, order–disorder transition, and compositional point defects on thermal conductivity. Thermal conductivity mapping of the beta-NiAl phase region of an Ni–Cr–NiAl diffusion triple clearly shows that Cr substitutes for both Ni and Al sites in beta-NiAl without a strong preference, which is also found not to be strongly composition dependent.

Micron-scale-resolution thermal conductivity mapping on graded compositions created in diffusion-multiple samples can be used to rapidly establish composition-phase-property relationships and to reveal the effects of solid-solutioning, order-disorder transition, compositional point defect, and site preference on thermal conductivity.Figure optionsDownload high-quality image (230 K)Download as PowerPoint slide