亚稳相的纳米尺度稳定化：热力学模型与实验研究

Nanoscale stabilization of metastable phase:thermodynamic model and experimental studies

建立了亚稳相合金的热力学模型,描述亚稳相的各种热力学物理量及其随成分、温度、晶粒尺寸等因素的变化.结合模型计算和系列实验,揭示了亚稳相的热力学性质、变化特征及其纳米尺度效应.以亚稳相SmCo_7合金为例,定量研究了亚稳相以单相形式稳定存在的条件及失稳发生的相分解行为.研究结果对亚稳相合金应用过程中相稳定性和相变的调控具有定量化指导意义.

A thermodynamic model, into which the nanoscale effect is introduced, is established to describe the thermal parameters of metastable phase, as well as their changes with the concentration, temperature and grain size. Based on the model calculations and experiments, the thermodynamic properties and dependence on the grain size are disclosed. Taking the metastable SmCor phase for example, the conditions for the single-phase stability and the phase decomposition are studied. The results are important for the control of the phase stability and phase transformation of the metastable-phase alloy.