Zhang Fan, Ilavsky Jan
Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.
X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA.
IUCrJ. 2024 Sep 1;11(Pt 5):675-694. doi: 10.1107/S2052252524006298.
Owing to their exceptional properties, hard materials such as advanced ceramics, metals and composites have enormous economic and societal value, with applications across numerous industries. Understanding their microstructural characteristics is crucial for enhancing their performance, materials development and unleashing their potential for future innovative applications. However, their microstructures are unambiguously hierarchical and typically span several length scales, from sub-ångstrom to micrometres, posing demanding challenges for their characterization, especially for in situ characterization which is critical to understanding the kinetic processes controlling microstructure formation. This review provides a comprehensive description of the rapidly developing technique of ultra-small angle X-ray scattering (USAXS), a nondestructive method for probing the nano-to-micrometre scale features of hard materials. USAXS and its complementary techniques, when developed for and applied to hard materials, offer valuable insights into their porosity, grain size, phase composition and inhomogeneities. We discuss the fundamental principles, instrumentation, advantages, challenges and global status of USAXS for hard materials. Using selected examples, we demonstrate the potential of this technique for unveiling the microstructural characteristics of hard materials and its relevance to advanced materials development and manufacturing process optimization. We also provide our perspective on the opportunities and challenges for the continued development of USAXS, including multimodal characterization, coherent scattering, time-resolved studies, machine learning and autonomous experiments. Our goal is to stimulate further implementation and exploration of USAXS techniques and inspire their broader adoption across various domains of hard materials science, thereby driving the field toward discoveries and further developments.
由于其卓越的性能，先进陶瓷、金属和复合材料等硬质材料具有巨大的经济和社会价值，在众多行业都有应用。了解它们的微观结构特征对于提高其性能、材料开发以及释放其未来创新应用的潜力至关重要。然而，它们的微观结构具有明确的层级性，通常跨越从亚埃到微米的多个长度尺度，这给其表征带来了艰巨的挑战，尤其是对原位表征而言，而原位表征对于理解控制微观结构形成的动力学过程至关重要。本文综述全面描述了快速发展的超小角X射线散射（USAXS）技术，这是一种用于探测硬质材料纳米到微米尺度特征的无损方法。当USAXS及其互补技术针对硬质材料进行开发并应用时，能为材料的孔隙率、晶粒尺寸、相组成和不均匀性提供有价值的见解。我们讨论了USAXS用于硬质材料的基本原理、仪器设备、优势、挑战和全球现状。通过选取的实例，我们展示了该技术在揭示硬质材料微观结构特征方面的潜力及其与先进材料开发和制造工艺优化的相关性。我们还对USAXS持续发展所面临的机遇和挑战发表了看法，包括多模态表征、相干散射、时间分辨研究、机器学习和自主实验。我们的目标是促进USAXS技术的进一步应用和探索，并激励其在硬质材料科学的各个领域得到更广泛的采用，从而推动该领域取得更多发现和进一步发展。
