【摘要】 采用分子动力学方法和QSC(quantumSutton-Chen)力场研究了升温速率对金属铅的熔化和过热行为的影响.模拟中考虑了缺陷和表面对熔化和过热行为的作用.结果表明,升温速率对金属铅的熔化和过热行为影响很大,随着升温速率的升高,金属铅的熔点有所升高.快的升温速率会导致金属铅体系内部无序化程度增加,进而使体系能量增加,降低了熔化相变的能垒.升温速率导致的金属铅的过热极限大约为780K.更多还原

【Abstract】 Molecular dynamics simulations are employed to study heating rate ind uced superheating and melting behaviors of bulk Pb. Quantum Sutton-Chen many bo dy potential is used for these simulations. The superheating and melting behavio r are found to be strongly affected by the heating rate, the rapid the heating r ate,the higher the melting temperature and there is an upper limit for the heati ng rate induce superheating. Stability study shows that heating rate induced ran domization is the main reason to eliminate the energy barrier for phase transfor mation to occur. Not only Pb crystals but also Pb crystals with defects are stud ied. And the upper limit of heating rate induced superheating is determined to b e around 780 K.更多还原