非晶材料玻璃转变过程中记忆效应的热力学

发布时间：2018-08-17 15:00

【摘要】：低温下处于非平衡态的非晶材料升温到玻璃转变以上,要先后发生弛豫和回复最终达到平衡过冷液态,其中弛豫过程中释放的能量在回复过程中以等量的方式获取,表现出明显记忆行为.本文基于氧化物、金属与小分子等多种非晶形成体系,全面探讨了在围绕玻璃转变的一个冷却加热循环过程中的焓弛豫特征,建立了弛豫谱,发现弛豫焓在数值上与熔化焓密切相关.基于弛豫焓与非晶材料动力学Fragility之间的关联,展示了非晶体系在动力学极限(m=175)条件下的玻璃转变热力学基本特征,与热力学二级相变进行了对比.研究深化了对非晶弛豫与玻璃转变热力学的理解.
[Abstract]:When the amorphous material in non-equilibrium state is heated to the glass transition at low temperature, the relaxation and recovery will occur successively to achieve the equilibrium supercooled liquid state, in which the energy released during the relaxation process will be obtained in the same amount during the recovery process. Show obvious memory behavior. Based on various amorphous systems such as oxides, metals and small molecules, the characteristics of enthalpy relaxation during a cooling and heating cycle around glass transition are discussed, and the relaxation spectra are established. It is found that the relaxation enthalpy is numerically closely related to the melting enthalpy. Based on the correlation between relaxation enthalpy and Fragility of amorphous material dynamics, the basic characteristics of glass transition thermodynamics of amorphous system under the kinetic limit (mb175) are shown, and compared with the second-order phase transition of thermodynamics. The study deepens the understanding of the thermodynamics of amorphous relaxation and glass transition.
【作者单位】：燕山大学材料科学与工程学院亚稳材料制备技术与科学国家重点实验室;
【基金】：国家重点基础研究发展计划(批准号:2015CB856805) 国家自然科学基金(批准号:11474247) 河北省自然科学基金(批准号:A2014203260)资助的课题~~
【分类号】：TG139.8

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