Measurement of rapid mass transport along individual dislocations in aluminum

摘要: Abstract Measurements were made of rapid mass transport by self-diffusion along individual dislocations in aluminum. Voids (200–400 A diameter) first produced throughout thin film specimens, and a number them “hooked-up” to the specimen surfaces which usual slip type with Burgers vectors b = 2〈110〉 . Upon subsequent annealing, electron microscope observations showed that atoms from diffused rapidly hooked-up voids causing anneal out more than isolated otherwise similar. An analysis void shrinkage rates measured between 50 180°C, assuming dislocation diffusion occurred via vacancies, yielded expression Λ d v AD T ξ 7.0 × 10 −17 exp (− 0.85eV kT ) cm 4 Sec −1 for average value self-diffusional parameter, Λdv, considerable making angles, θ, respect over range at least 20° ⪯ θ 80°. Here, effective area, DTd tracer self-diffusivity ξTd correlation factor. similar result, (within factor two) was obtained using phenomonological independent mechanism. The Λvd data relatively large scatter, no systematic variation evident. It concluded any 80° less ten. results compared selected existing measurements dislocations, it pointed not inconsistent vacancy mechanism temperature magnitude order few tenths.