Abstract
Internal oxidation by Rhines Pack method was introduced to produce the dispersion strengthened Cu-Al alloy. Three Cu-Al alloys with different Al content, namely Cu-0.33wt% Al, Cu-0.86wt% Al and Cu 1.50wt% Al, were used in this work. The specimens were prepared in two thickness. The thicker samples, which were 400 mm, were used to study the conical colony phase found in the earlier study. The thinner specimens, which were 200 mm, were used to study the effects of the specimen thickness. In the 400 mm specimens, the conical colonies could be observed. The formation of the phase were influenced by the treated temperature and time and the Al content. In the Cu-1.50wt.% Al specimens, both the oxide film and the conical colonies could be observed, and the conical colonies were found to be near the oxide film. In the Cu-0.33wt.% Al specimens, no conical colonies were found. In the Cu-0.86wt% Al specimens, it was found that when the treated temperature was higher than 840 ℃, the conical colonies grew larger as the time increasing. With the X-ray diffraction analysis, the conical colonies were found to contain CuAlO2. In the 200 mm specimens, neither the oxide film nor the conical colonies were found in the Cu-0.33wt % Al and the Cu-0.86wt % Al specimens. Compared to the 400mm specimens, the internal oxidation reaction followed parabolic law and thus the completion time of the specimens could be predicted. In the Cu-1.50wt % Al specimens, the internal oxidation can be completed even with the existence of the oxide film.