摘要
建立了纳米晶合金的热力学性质随温度和晶粒尺寸变化的函数关系。通过计算分析了Li2C2纳米晶合金的吉布斯自由能随温度和晶粒尺寸的变化,研究了其相稳定性和相变特征。模型预测结果显示,当晶粒尺寸减小到100 nm以下时,相变温度均低于粗晶块体材料的相变温度,且随晶粒尺寸的减小而进一步降低。在室温下(300 K),当晶粒尺寸减小至约6 nm及以下时,传统高温稳定相β-Li2C2相可以在室温下稳定存在。
The relationship that the thermodynamic characteristics of nanocrystalline alloy change with the temperature and nanograin size is deduced in this article. Take the Li2C2 alloy as an example, the phase stability and phase transformation behavior were studied based on the calculated Gibbs free energy determined distinctly as a function of temperature and nanograin size. The results showed that the phase transformation temperature is lower than that of polycrystalline alloy when the grain size is smaller than 100 nm. Furthermore, the phase transformation temperature decreases obviously with the decreasing nanograin size. High temperature phase 13-Li2C2 can exist stably at room temperature （300 K） when the grain size is smaller than 6 nm.
出处
《中国体视学与图像分析》
2012年第4期361-365,共5页
Chinese Journal of Stereology and Image Analysis
基金
北京市自然科学基金(2112006)
德国国家研究联合会基金(SPP 1473-SO 1075/1-1)
关键词
纳米热力学
纳米晶Li2C2
相稳定性
nanoscale thermodynamics
nanocrystalline Li2C2
phase stability
