中子表征技术在金属结构材料研究中的应用

Application of Neutron Characterization Techniques toMetallic Structural Materials

结构材料的原子结构、微观组织与宏观性能的关联性是材料研究的核心问题之一,历久弥新。近年来,加速器基中子源大科学装置的建设和相关实验技术取得了长足进步,这为在实时原位条件下深入研究该问题提供了良好的基础。本文介绍了中子衍射、Bragg边成像、小角中子散射、对分布函数分析、准弹性/非弹性中子散射等主要中子表征技术在结构材料中应用的最新进展,着重论述了钢铁材料相变内应力起源与演化、镁合金等轻金属材料的变形机制、基于Bragg边成像的微观结构及残余应力分析,并对今后发展趋势进行了简要展望。

The correlation between the atomic structure,microstructure,and macroscopic properties of structural materials remains a core issue in materials research.In recent years,substantial progress has been achieved in constructing accelerator-based neutron sources and related experimental techniques,offering a robust platform for an in-depth understanding of the aforementioned correlation under real-time and in situ conditions.This article reviews the latest advancements in the application of major neutron characterization techniques,including neutron diffraction,Bragg-edge imaging,small-angle neutron scattering,pair distribution function analysis,and quasi-elastic/inelastic neutron scattering,in structural materials.Furthermore,it particularly highlights the origins and evolution of internal stresses during the phase transformations of steels,deformation mechanisms in light metals such as magnesium alloys,and microstructure and residual stress analyses using Bragg-edge imaging.Finally,a brief outlook on future development trends is provided.