Diffusion of Mass in Liquid Metals and Alloys – Recent Experimental Developments and NewPerspectives

Int. J. Microgravity Sci. Appl. 2013p030
Author
A. MEYER and F. KARGL
Organization
Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Abstract
Despite its tremendous importance for the understanding of underlying mechanisms and for the input in modeling and simulation of processes alike, accurate experimental diffusion data in liquid metals and alloys are rare. Common techniques exhibit several drawbacks that in most cases prevent an accurate measurement of diffusion coefficients - convective contributions during diffusion annealing are the most prominent ones. Recently, we advanced the field of liquid diffusion experiments through the use of quasielastic neutron scattering (QNS) on levitated metallic droplets for accurate measurements of self-diffusion coefficients in high-temperature metallic liquids. For the accurate measurement of interdiffusion coefficients we combine long-capillary experiments with an in-situ monitoring of the entire interdiffusion process by the use of X-ray and neutron radiography. These experiments are accompanied by diffusion experiments in space in order to benefit from the purely diffusive transport under microgravity conditions. Recent experimental results are discussed in the context of the relation of self- and interdiffusion (Darken’s equation) and of the relation of self-diffusion and viscosity (Stokes-Einstein relation).
Keyword(s)
liquid metals, self-diffusion, interdiffusion, long-capillary, shear-cell, X-ray radiography, quasielastic neutron scattering
PDF
Download

© The Japan Society of Microgravity Applicaiton

この投稿文は次の言語で読めます: Japanese

ページ先頭に戻る