熵作为系统的状态函数,对于真实物质体系而言是一个极为重要的物理量.在非晶态合金的制备过程中最具代表性的指导原则有"混乱原理"和井上三原则,二者皆与熵有着紧密的联系.在过去很长一段时间内,这些经验准则指导了大量新型非晶体系的发现,但近些年的实验结果对这些理论提出了质疑.除组元数目之外,还有其他尚待研究的因素也影响着合金体系的玻璃形成能力.本文总结了玻璃转变过程中熵在热力学条件、动力学条件和结构条件中所扮演的角色,阐述了其对玻璃形成能力产生的或正或反的影响.特别是对近几年发展起来的高熵非晶体系的研究有助于开发出临界尺寸更大的非晶合金,也有助于进一步探索多组元合金和非晶形成能力之间的关系.%Entropy is a state function of the real physical system, which relates to the chaos of a system. During the long-term exploring glass-forming systems, many empirical rules are put forward, including "confusion principle" and three empirical rules. Over a long period of exploring, many glass-forming alloys are developed based on those principles, while some questions have been raised in recent years based on the experimental results, because some other uncertain factors also have influence on the glass-forming ability (GFA) except a number of constituents, e.g., entropy. Greer claimed that in the "confusion principle" the higher the entropy value, the better the glass-formation ability will be, which does not accord with the recent experimental results. The effects of entropy on the glass-formation ability are summarized from the viewpoints of thermodynamics, kinetics, and complexity of atomic structures. In the aspects of thermodynamics and structure, the increase of entropy has a positive effect on glass formation, while in kinetics, the influence is negative. From the viewpoint of thermody-namics, the increase of entropy leads to the decrease of the entropy difference between solid phase and liquid phase, and therefore, the difference in Gibbs free energy between these two phases decreases. At a certain time during solidification, compared with the low-entropy alloy, the high-entropy alloy in the solid phase has an atomic arrangement close to that in the liquid, and it is more likely to form the amorphous phase. In the aspect of kinetics, the increase of entropy results in the decrease of the viscosity of the system according to the Adam-Gibbs equation. As a result, atoms diffuse easily in the system and the ordered-phase is more likely to form, which means that the glass-formation ability decreases with the increase of entropy. Furthermore, in the aspect of atomic structure, the increase of mismatch entropy relates to the big misfit degree between atoms, i. e. , the large atomic size difference. Atoms in the high-entropy alloy tend to distribute disorderly in the system, and therefore the stress between atoms increases. As a result, with the increase of the entropy, the ordered-phase becomes unstable and the GFA will be enhanced. Furthermore, the high-entropy-glass is briefly reviewed and analyzed, which is a new system between high-entropy alloy and amorphous alloy. There have been many high-performance high-entropy-glass systems reported up to now. Re-searches about this unique system will contribute to developing some new amorphous alloys with excellent performances, and more importantly, to exploring the complex relationship between GFA and multicomponent alloys.
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