热力学与动力学相关性,科学与人文的统一

金属热加工通过相变决定材料最终组织和性能。随着非平衡技术的快速发展,热加工工艺趋于极端化和多样化,控制相变的热力学与动力学机制从简单近平衡条件下的相对独立转变为复杂远平衡条件下的高度关联。基于热-动力学独立处理的传统理论已无法应对上述相变涉及的机理描述、组织预测和过程控制。随着催化剂研究体系的扩展,传统的基于独立的反应动力学或吸附热力学的设计已无法满足催化剂的高性能需求与高效筛选。本文从人文领域中的激情与困难的逻辑关系中,引申出科学领域中的热力学驱动力与动力学能垒的相关性,针对非平衡凝固过程、晶界迁移及晶粒长大热稳定性、纯Fe沿Bain路径的马氏体切变,整理出热力学驱动力与动力学能垒的定量关联,建立了组织预测模型,提出了热-动力学协同作用的新理念,并据此设计出高性能DD3高温合金、Fe基纳米晶材料、A356铝合金和应变态电催化材料。

Correlation between thermodynamics and kinetics: unification of science and humanity#br#

The final microstructure and property of metallic materials are determined by hot-working, in terms of phase transformations. With rapid development of the non-equilibrium technology, the processing of hot-working becomes extreme and versatile, so that the thermodynamics and kinetics of phase transformation is changed from the inter-independence corresponding to brief near-equilibrium process to the highly correlation corresponding to complicated extremely non-equilibrium process. Accordingly, the classical theory, basing on the independent treatment of thermodynamics and kinetics, is unsuitable to describe the mechanism, predict the microstructure and control the process. In addition, as the research system expansion of catalysts, the traditional design strategy based on independent reaction kinetics or adsorption thermodynamics is incapable of meeting the high-performance demands of catalysts and their efficient screening. As a result, extended from the logical relationship between passion and difficulty in the humanities, the correlation between the thermodynamic driving force and kinetic energy barrier is raised in this review. Focusing on non-equilibrium solidification, thermal stability of grain boundary migration and grain growth, martensitic transition in Fe via Bain path, the correlation between thermodynamics and kinetics is quantitatively summarized, and the microstructure prediction model is set up. The new concept of thermo-kinetic synergy is raised, based which the design and preparation of DD3 alloy, nanostructured Febased alloy, A356 aluminum alloy and strained electrocatalysts are reviewed.