The surface tension of molten AlSi20 alloy has been measured by using the sessile drop method at 923―1123 K under argon atmosphere in both heating-up and cooling processes. The result shows that the surface tension o...The surface tension of molten AlSi20 alloy has been measured by using the sessile drop method at 923―1123 K under argon atmosphere in both heating-up and cooling processes. The result shows that the surface tension of this alloy decreases as long as temperature increases. The results of surface tension and contact angles in heating-up process have differences from those obtained in cooling process, because the metal microstructures have some changes at different temperatures based on the metal genetic theory. The surface tension of molten AlSi20 alloy and that of molten pure aluminum have been compared as well, and the temperature coefficient of AlSi20 alloy is slightly lower than that of Al. The result has been analyzed by the linear scanning analysis with ESEM. The concentration of silicon in most region of the bulk is lower than that of the surface and the addition of Si to pure Al decreases the surface tension of molten pure Al.展开更多
为建立煤的吸附特性与表面能的定量关系,利用悬滴法恒温27℃测试不同浓度下的APG(烷基糖苷)溶液表面张力,以及利用躺滴法测试临界胶束浓度下APG溶液在煤表面的平衡接触角,进而计算出煤的表面能。研究结果表明:APG溶液在煤表面形成的接...为建立煤的吸附特性与表面能的定量关系,利用悬滴法恒温27℃测试不同浓度下的APG(烷基糖苷)溶液表面张力,以及利用躺滴法测试临界胶束浓度下APG溶液在煤表面的平衡接触角,进而计算出煤的表面能。研究结果表明:APG溶液在煤表面形成的接触角远小于水在煤表面形成的接触角,同时随着煤变质程度的提高呈现先增大后减小的趋势,这是APG分子与煤之间分子间作用力及煤表面疏水官能团联合控制的结果;随着煤样变质程度的提高,煤的表面能与吸附常数a皆呈现先减小后增大的趋势;表面能随吸附常数a的增大较好的服从指数函数变化规律,根据回归模型,煤的表面能最后趋近于35.63 m N/m。展开更多
基金the National Natural Science Foundation of China (Grant Nos. 50474043 and 50711140385)
文摘The surface tension of molten AlSi20 alloy has been measured by using the sessile drop method at 923―1123 K under argon atmosphere in both heating-up and cooling processes. The result shows that the surface tension of this alloy decreases as long as temperature increases. The results of surface tension and contact angles in heating-up process have differences from those obtained in cooling process, because the metal microstructures have some changes at different temperatures based on the metal genetic theory. The surface tension of molten AlSi20 alloy and that of molten pure aluminum have been compared as well, and the temperature coefficient of AlSi20 alloy is slightly lower than that of Al. The result has been analyzed by the linear scanning analysis with ESEM. The concentration of silicon in most region of the bulk is lower than that of the surface and the addition of Si to pure Al decreases the surface tension of molten pure Al.
文摘为建立煤的吸附特性与表面能的定量关系,利用悬滴法恒温27℃测试不同浓度下的APG(烷基糖苷)溶液表面张力,以及利用躺滴法测试临界胶束浓度下APG溶液在煤表面的平衡接触角,进而计算出煤的表面能。研究结果表明:APG溶液在煤表面形成的接触角远小于水在煤表面形成的接触角,同时随着煤变质程度的提高呈现先增大后减小的趋势,这是APG分子与煤之间分子间作用力及煤表面疏水官能团联合控制的结果;随着煤样变质程度的提高,煤的表面能与吸附常数a皆呈现先减小后增大的趋势;表面能随吸附常数a的增大较好的服从指数函数变化规律,根据回归模型,煤的表面能最后趋近于35.63 m N/m。
