摘要
本工作利用表面能与内聚能的比例关系,计算了液态Ag的表面张力和表面过剩熵。结果显示,随着温度的升高,表面张力近似线性下降,表面过剩熵也逐渐减小,这表明液态Ag表面总是保持有序结构。在此基础上,证明了Ag-O系具有理想溶体性质,并简化了Butler方程,修正了液态Ag-O系表面张力关于氧气压力和温度的预测模型。结果表明,当氧气压力低于10 kPa时,液态Ag-O系的表面张力与温度呈负相关;而当氧气压力高于10 kPa时,随着温度的升高,表面张力呈现先增大后减小的趋势。此外,还探究了O原子的表面偏析行为。研究发现,表面偏析因子与温度和氧气压力均呈负相关,在较低的温度和氧气压力下,O原子倾向富集于表面。
Surface tension,an important physical parameter of liquid metals,plays a crucial role in governing various surface phenomena.In this work,the surface tension and surface excess entropy of liquid silver were calculated using the proportion relationship between surface energy and cohesive energy.The results showed that as the temperature increased,the surface tension approximately linearly decreased,and the surface excess entropy also gradually decreased,which indicated that the liquid silver surface always maintained an ordered structure.On this basis,the liquidus line of the Ag-O system was calculated using the ideal solution approximation model,and its agreement with the experimental phase diagram validated that the system could be considered as an ideal solution.By simplifying the Butler equation,a predictive model for the surface tension of the liquid Ag-O system as a function of oxygen partial pressure and temperature was derived.The results demonstrated that at oxygen partial pressures below 10 kPa,the surface tension of the liquid Ag-O system showed a negative correlation with temperature.However,for oxygen partial pressures above 10 kPa,the surface tension initially increased and then decreased with the increasing temperature.Additionally,the surface tension of the liquid Ag-O system at 1350 K was calculated and compared with literature data,showing excellent agreement between the calculated values and experimental observations.Furthermore,the surface segregation behavior of oxygen atoms was also investigated.The study revealed that surface excess concentration was positively correlated with oxygen partial pressure and negatively correlated with temperature.It was observed that the surface segregation factor showed negative correlations with both temperature and oxygen partial pressure.At lower temperatures and oxygen pressures,oxygen atoms tend to accumulate on the surface.This research provides data support for deep exploration of the surface properties of the liquid Ag-O system and serves as a reference for optimizing predictive models of surface tension in metal-gas systems.
作者
李天骕
刘剑雄
单显祥
李堪鹏
Tiansu LI;Jianxiong LIU;Xianxiang SHAN;Kanpeng LI(School of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming,Yunnan 650500,China)
出处
《过程工程学报》
CAS
CSCD
北大核心
2024年第4期453-461,共9页
The Chinese Journal of Process Engineering
