Wetting of the (0001) 伪-Al₂O₃ Sapphire Surface by Molten Aluminum: Effect of Surface Roughness

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• 作者：Joaquin Aguilar-Santillan (12) joaquin.aguilar-santillan@intel.com
• 刊名：Metallurgical and Materials Transactions A
• 出版时间：March 2010
• 出版年：2010
• 期刊代码：pc363_1073-5623
• 类别：ch
• 卷：41
• 期：3
• 页码：676-685
• 数据来源：sp

摘要

The wetting of molten aluminum on the “c”-plane (0001) of single-crystal α-Al₂O₃ (sapphire) was studied by the sessile drop technique from 800 掳C (1073 K) to 1200 掳C (1473 K). Systematically increasing the (0001) surface roughness by SiC abrasion increased the wetting contact angle, resulting in reduced wetting. The surface roughness factor R originally defined by Wenzel, was determined as a function of the abrasion, temperature, and time. The wetting decreases as the surface roughness increases. Rough surfaces also create time and temperature effects on wetting, changing those for a smoothly polished surface. The existence of a high-temperature surface structural transition for (0001) of α-Al₂O₃, which has been previously suggested, was confirmed. Increased roughness R accents the effect of the surface structural transition, increasing the wetting contact angle changes during the transition.