Energetics and atomic transport at liquid metal/Al2O3 interfaces

✍ Scribed by E Saiz; R.M Cannon; A.P Tomsia

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 250 KB
• Volume: 47
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(99)00279-7

✦ Synopsis

AbstractÐThe objective is to study interfacial mass transport mechanisms and to estimate interfacial energies for metal/Al 2 O 3 systems. Experiments have been performed with molten drops of Ni, Cu, or Au on pure, polycrystalline alumina at oxygen partial pressures for which no adsorption is expected and with Al to determine the eect of extremely low p(O 2 ). After removing the metal drops, grain boundary grooves at the interface and oxide surface have been analyzed using AFM and SEM. Several sources of error are assessed, and corrections are proposed for large systematic errors that occur for root angles. These experiments yield higher grain boundary energies and lower M/Al 2 O 3 interfacial energies than previously reported. Transport rates near the metal/ceramic interface are two to four orders of magnitude faster than on the oxide surface and the results suggest that diusion through the liquid metal is usually the main atomic transport mechanism. Experiments with Al indicate that, at the far lower oxygen activities, transport is faster at both the interface and alumina surface and that the interfaces are more anisotropic and have lower energy.