|About this Abstract
||2010 TMS Annual Meeting & Exhibition
||Computational Thermodynamics and Kinetics
||Compositional Point Defect Evaluation using Diffusion Multiples
||Ji-Cheng Zhao, Xuan Zheng, David G. Cahill
|On-Site Speaker (Planned)
Compositional point defects such as vacancies and anti-sites have a significant effect on the properties of alloys and intermetallic compounds. For instance, point defects in NiAl result in orders of magnitude change in diffusion coefficients. Two indirect ways to find the formation of compositional point defects in alloys and intermetallics using diffusion couples and diffusion multiples will be discussed. The first involves micron-scale thermal conductivity mapping over a wide range of compositions. A sharp change in thermal conductivity in a very narrow range of composition is indicative of compositional point defect formation. Thermal conductivity measurements can also be used to study the site preference / elemental substitution in intermetallic compounds. The second method looks at the shape of the diffusion profiles and the dependence of diffusivity on composition. Examples will be used to illustrate these methodologies. Both methods are sufficient, but not necessary tests of the compositional point defects.
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