Berlin 2008 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 41: Poster SYM Hydrogen in Materials: New Developments
MM 41.13: Poster
Donnerstag, 28. Februar 2008, 18:00–20:00, Poster B
Microstructure and electrical conductivity of Cu-Ti alloys aged in hydrogen atmosphere — •Satoshi Semboshi1,2, Ryota Gemma2, Talaat Al-kassab2, Astrid Pundt2, and Reiner Kirchheim2 — 1Materials Science and Engineering, Osaka Prefecture University — 2Institut für Materialphysiks, Uni. Göttingen
The influence of the aging in a hydrogen atmosphere on the electrical properties of Cu-1 and 3 at. % Ti alloys was investigated by means of electrical conductivity measurements and structural measurements using the X-ray diffraction, transmission electron microscopy and atom probe tomography. In the Cu-3 at.%Ti alloy, aging for 48 hours at 773 K in hydrogen atmosphere leads to an improvement of the electrical conductivity up to 65 % IACS (International Annealed Copper Standard), in comparison the value obtained for the alloy aged in a vacuum atmosphere. In addition, aging in hydrogen atmosphere leads to an efficient decrease of the lattice parameter of the Cu solid solution (Cuss) phase, suggesting a significant decrease of the Ti concentration in the Cuss phase. An important structural finding is the existence of not only a needle-shaped Cu$_4$Ti phase but also some cuboidal TiH$_2$ phase precipitates in the alloy aged in the hydrogen atmosphere. We, therefore, conclude that the aging in a hydrogen atmosphere strongly promotes the depletion of Ti in the Cuss phase because of the Cu$_4$Ti and TiH$_2$ precipitates formation, resulting in the significant improvement of the electrical conductivity. This work is partly supported by Inamori Foundation in Japan.