1Faculty of Science, Osaka City University, Osaka
The effects of addition of small amount of Mn on the aging process of Al-Cu alloys were studied. The change of electrical resistance during aging were measured at liquid nitrogen temperature, and thin foils made from as quenched alloys were examined by transmission electron microscopy. Results obtained were as follows: (1) The time law of the resistance change was not altered by addition of Mn, and low temperature aging was caused by the formation of G.P.zones of the same kind as Al-Cu. (2) Aging rate was slightly decreased by addition of Mn. (3) It was observed by transmission electron micrography that the number and diameter of helices and loops of dislocation in specimens containing Mn had a resemblance to those in specimens of Al-Cu alloy of lower copper content. (4) Binding energy between a Mn atom (or a pair of Mn-Cu) and a vacancy might be smaller than the sum of binding energy between a Cu atom and a vacancy in eV and 0.1 eV.
Please do not copy without permission.