| Titre : | Grain boundary self-diffusion in polycrystalline nickel of different purity levels |
| Auteurs : | Sergiy V. Divinski, Auteur ; Gerrit Reglitz, Auteur ; Gerhard Wilde, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Acta materialia (Vol. 58 N° 2, Janvier 2010) |
| Article en page(s) : | pp. 386-395 |
| Note générale : | Métallurgie |
| Langues : | Anglais |
| Index. décimale : | 669 (Métallurgie) |
| Tags : | Nickel Grain boundary diffusion segregation width |
| Résumé : |
Grain boundary self-diffusion in Ni materials of two different purity levels (99.6 and 99.999 wt.%) was measured over wide temperature intervals using the radiotracer technique and applying the 63Ni radioisotope.
The diffusion experiments were performed in both Harrison’s type B and type C kinetic regimes. The diffusional grain boundary width, δ, was found to be equal to 0.54 ± 0.1 nm, that is reasonably close to the accepted value of View the MathML source in face-centred cubic metals. The purer the material, the higher the grain boundary diffusivity and the lower the corresponding activation enthalpy of self-diffusion along general high-angle grain boundaries. Using the semi-empirical approach of Borisov et al., the average energy of high-angle grain boundaries was estimated to be about 0.79 and 0.98 J m−2 in the low- and high-purity Ni materials at room temperature, respectively. |
| DEWEY : | 669 |
| ISSN : | 1359-6454 |
| En ligne : | http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235556%232010%23999419997%231562200%23FLA%23&_cdi=5556&_pubType=J&_auth=y&_acct=C000070790&_version=1&_urlVersion=0&_userid=6909337&md5=b76b02a9bf437ba6ba8077be7b9830f5 |
