非晶合金稳定性研究及其高稳定非晶合金的探索

The study on the thermal stability and relaxation of amorphous alloys has been an important topic in amorphous materials and physics. First of all, the stability of amorphous alloys is related to the method of formation amorphous, and the processing by thermal relaxation and other treatments can adjust or control the stability of amorphous alloys. The project seeks to carry out investigation on amorphous alloys stability and exploration of high stability of amorphous alloys. By applied stress or strain, relaxation and rejuvenation processes on the amorphous alloys with different forming conditions, we will study the characteristics, structure and related properties of thermodynamics and kinetics. In this project, the sensitivity of glass transition temperature of amorphous alloy on heating rate will be used as a way of evaluating the stability of amorphous alloy. Through the implement of this project, the relationships between thermal stability and glass transition temperature, enthalpy change and other physical and thermodynamic parameters will be revealed, and the main parameters of thermal stability of amorphous alloy will be obtained. Based on the study of the thermal stability of amorphous alloys, a new type of amorphous alloys with high thermal stability would be prepared, and our results will provide the theoretical direction for the design of new high performance and high stability amorphous alloys.

对非晶合金的热稳定性与驰豫处理研究一直是非晶材料与物理及应用研究的重要主题。非晶合金的稳定性首先与非晶合金的形成方式有关，驰豫等处理会调控非晶合金的热稳定性。本项目提出开展非晶合金稳定性与探索高稳定性非晶合金的研究工作。通过对不同形成状态的非晶合金在不同温度进行施加应力或应变、驰豫与恢复处理，研究发生的热力学与动力学行为特性、结构和相关的性能演变。本项目提出将非晶合金的玻璃转变温度Tg对加热速度敏感性作为评价非晶合金（热）稳定性的思路。通过本项目的研究，揭示其热稳定性与玻璃转变温度及焓变等物理和热力学参数之间的关系，获得表征非晶合金热稳定性的主要参量。在研究非晶合金热稳定性基础上，探索制备出新型高热稳定性非晶合金，并为新型高性能高稳定非晶合金的设计提供理论指导。

本课题通过制备非晶合金的三种主要方法及采用弛豫、结构和计算机模拟等手段研究了非晶合金的热稳定性及其相关性质和性能变化。标准本课题获得的有科学与应用价值的成果主要体现在在如下几点：1）目前制备非晶合金的3种主要方法中，不需要后续处理而能获得的非晶合金其热稳定性（这里以Tg高低来表述）顺序为：Tg薄膜>Tg块体>Tg薄带，气相沉积方法在制备过程中就可以获得高温定乃至产稳定的非晶合金，但制备过程非常之慢；2）低温退火处理在提高其热稳定性的同时可以揭示隐含的β弛豫，退火获得非晶样品热稳定性越高其焓变即热力学能态越低；3）采用高低温循环加热与冷却揭示出在加热过程中出现快β’弛豫峰现象；4）高压下金属玻璃的热稳定性与热膨胀系数及波色峰温度变化关系呈非单调性，高压在控制金属玻璃的热稳定性的同时可获得负、零和正膨胀材料；5）计算机模拟发现金属玻璃的超低温快β’弛豫峰。本工作结果对于认识非晶合金的热力学及动力学超稳定性问题的本质及其更广泛和全面了其解弛豫特性具有明显的科学价值，为探索改进非晶合金的性能及探索新的应用提供了重要参考。