The influence of surface structure on wetting of α-Al2O3 by aluminum in a reduced atmosphere

✍ Scribed by Ping Shen; Hidetoshi Fujii; Taihei Matsumoto; Kiyoshi Nogi

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 281 KB
• Volume: 51
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(03)00332-x

✦ Synopsis

An improved sessile-drop wetting experiment was performed in this study to investigate the wettability and adhesion of molten Al on three different oriented a-Al 2 O 3 single crystals, R (0112), A(1120) and C(0001), over a wide temperature range from 800-1500 °C in a reduced Ar-3%H 2 atmosphere. It is found that the wettability and adhesion between molten Al and a-Al 2 O 3 are quite sensitive to the crystallographic orientation. The adhesion is much stronger for the molten Al on the R and A surfaces than that on the C surface. On the other hand, the adhesion on the reconstructed C-(√31 × √31)R ± 9 ‫ؠ‬ surface is weaker than that on the relaxed yet unreconstructed C-(1 × 1) surface. The results suggest that in the reduced Ar-3%H 2 atmosphere, the top layers of the R and A a-Al 2 O 3 surfaces are oxygen-terminated while that of the C surface is aluminum-terminated, and the reconstructed C-(√31 × √31)R ± 9o surface is an oxygendeficient structure based on the results of the work of adhesion.