显微组织三维重构技术在材料科学研究领域中的应用

材料显微组织三维重构与定量表征是材料科学与工程领域的焦点与核心之一。该方法可将材料的内部结构信息及其与性能之间的关系直观地呈现出来,对全面认识材料微观结构并建立材料组织与性能之间的定量关系具有重要作用。总结了国内外关于显微组织三维重构技术在材料研究领域中的应用,并阐述了各种方法,分析比较了各自的优缺点,寻求高精度材料微观组织三维重构方法,有利于促进材料微观组织形态由二维定性表征向三维定量表征的过渡。     

基于连续切片的三维重构技术在材料凝固组织研究中的应用

讨论了在材料科学与工程研究中进行三维重构的意义和必要性,介绍了基于连续切片的三维重构技术的理论、方法及在材料科学与工程中的研究和应用进展.指出基于切片的三维重构技术对材料凝固过程中微观结构定量分析、微观组织-性能的研究提供了有力支持,结合数值模拟技术可为材料凝固过程中复杂组织的形成机理及凝固理论的发展提供理论和精确的实验依据,从而对新材料的设计与开发产生重要作用.最后简要介绍了三维重构技术在定向凝固过程中多相组织分析的应用,并展望了三维重构技术的发展方向.     

材料微观组织结构三维模拟的研究进展

多晶体材料微观组织结构很大程度上决定了其宏观物理力学性能，材料微观组织的模拟对于研究和预测材料的宏观力学性能具有重要意义。随着计算机技术的发展，材料微观组织的三维模拟已成为材料微观组织模拟的研究热点。总结了材料微观组织三维模拟的方法及其应用，提出了三维模拟的研究方向。     

基于三维重构的材料微观结构研究现状

讨论了材料科学进行三维重构的意义和必要性,详细介绍了基于三维重构的材料微观结构研究的4个步骤:二维图像的获取、二维图像的处理、三维重构和材料微观结构研究.提出由于基于三维重构的材料微观结构研究材料能够分析出材料的宏观力学性能对微观结构的依赖关系,所以进行基于三维重构的材料微观结构研究方法能够对复合材料的设计提供有力的支持.     

机器学习技术在材料科学领域中的应用进展

材料是国民经济的基础,新材料的发现是推动现代科学发展与技术革新的源动力之一,传统的实验"试错型"研究方法具有成本高、周期长和存在偶然性等特点,难以满足现代材料的研究需求.近些年,随着人工智能和数据驱动技术的飞速发展,机器学习作为其主要分支和重要工具,受到的关注日益增加,并在各学科领域展现出巨大的应用潜力.将机器学习技术与材料科学研究相结合,从大量实验与计算模拟产生的数据中挖掘信息,具有精度高、效率高等优势,给新材料的研发和材料基础理论的研究提供了新的契机.机器学习技术结合了计算机科学、概率论、统计学、数据库理论以及工程学等知识,计算速度快、泛化能力强,能有效地处理一些难以运用传统实验及模拟计算方法解决的体系和问题.近10年,机器学习在材料科学研究中的应用呈现出爆炸式的增长,尤其在新材料的合成设计、性能预测、材料微观结构深入表征以及改进材料计算模拟方法几个方面,均有着出色的表现.当然,作为一项数据驱动技术,如何获取大量实验数据并将其构建为行之有效的数据集仍是现阶段机器学习技术在材料科学领域应用的热点和难点.本文概述了机器学习技术的基本原理、主要工作流程和常用算法,简述了机器学习技术在材料科学领域中的研究重心及应用进展,分析了机器学习在材料学研究中尚存在的问题,并对未来此领域的发展热点进行了展望.     

三维石墨烯及其复合材料的制备及在超级电容器中的研究进展

三维(3D)石墨烯及其复合材料具有柔韧性好、比表面积大、功率密度高、力学性能稳定以及离子传输迅速等优良性能,成为材料科学领域备受关注的材料。概述了三维石墨烯材料的基本性质和性能,并对其多元复合材料的制备方法以及在超级电容器储能材料方面的应用研究进展进行了评述。三维(3D)石墨烯常用的制备方法有自组装法、模板导向法和3D打印法等,通过对制备方法进行改进,可以有效调控三维材料的多孔结构、孔径、柔韧性和电子传递速度等性能。三维(3D)石墨烯与过渡金属化合物及导电聚合物复合而成的多元复合物在超级电容器电极材料方面表现出广阔的应用前景。     

金属半固态浆料非枝晶微观组织形成机制与表征

半固态技术自20世纪70年代由麻省理工学院开发以来,因其独特的优势而在全球范围内得到了广泛的研究。非枝晶组织的形成机理是半固态成形技术的基石,它决定了在特定条件下应采用哪些工艺来获得优质的半固态组织,对开发新工艺具有重要的指导作用。经过近半个世纪的发展,半固态浆料制备过程中非枝晶结构的形成机理已经发展出许多不同的观点。由此衍生了丰富的半固态浆料制备技术,大大促进了半固态领域的发展。为了进一步理解凝固过程中球晶的形成机制,对各种非枝晶组织的形成机制进行了梳理,基于制备原理将半固态制浆技术分为搅拌制备技术类和低过热度制备技术类,并对常见的几种技术的原理和应用进行了总结。半固态产品的性能在很大程度上取决于其微观组织结构,但半固态形态复杂,传统的二维表征手段对材料内部空间结构的理解可能存在误差。对半固态浆料的二维微观组织和三维显微组织表征技术进行总结分析,为理解金属半固态浆料的微观结构演变和微观组织与性能之间的关系提供了理论基础。     

X-ray成像技术表征金属凝固组织及其演化过程研究进展

X-ray具有较强的穿透性,可以穿透一定厚度的金属块状材料(毫米级的重金属,如钢、镍基合金等和厘米级的轻质金属,如铝、镁合金等),因而可以用来对其进行成像,获得其内部二维和三维微观结构。X-ray成像技术对被表征物体的成像是非破坏性的(non-destructive),因而在一定的时间和空间分辨率条件下,还可以对金属材料成形过程的组织演化实时观测,实现对金属材料成形过程宏/微观结构演化的原位表征。第三代同步辐射光源可以产生高通量、高能量、高分辨率以及高相干性的X-ray光束,利用它可以实现对金属材料从宏观(厘米级)到微观(微米、亚微米、纳米级)结构及其演化过程快速、准确的测量表征。X-ray成像技术已经成为研究金属凝固科学问题的有力手段。简介了X-ray成像技术的基本原理,综述了X-ray成像技术在金属凝固组织三维(3D)表征和组织演化过程二维和四维(3D+时间)原位表征中的应用。最后对未来X-ray成像技术在金属材料凝固领域的应用前景进行了展望。     

基于CT的准脆性材料三维结构重建及应用研究

准脆性材料的结构及其细观组分的力学性质决定了材料的力学性质及破裂机制,在数值模型中尽可能准确的考虑材料的真实结构已成为了数值计算与数值模拟发展的一种趋势。该文以混凝土为研究对象,借助于先进的CT技术获取混凝土内部结构切片图像,利用数字图像处理技术实现了基于CT图像的混凝土材料结构的识别和表征,并针对CT图像具有颜色亮度不均并呈环状分布的特点,提出了环状分区与分割阈值自动识别相结合的CT图像分割算法;在此基础上,建立了基于位图矢量化理论的三维实体材料结构模型的重建方法和三维网格化材料结构模型重建方法,并将三维网格化方法建立的材料结构模型与三维岩石破裂过程分析系统RFPA3D结合进行了初步应用,对混凝土单轴压缩破裂过程进行了数值模拟。通过数值试验与物理实验结果对比发现,考虑混凝土骨料真实分布的数值实验结果与物理实验具有一定可比性,数值试验结果从得到的力学参数和破裂模式方面比较接近于物理实验结果,为深入研究混凝土、岩石、复合材料等力学特征提供了一种可行的研究思路。     

多孔材料的孔结构表征及其分析

多孔材料的研究已成为当今材料科学研究领域的一大热点,而多孔材料的研究离不开结构表征分析.多孔材料的表征常用X射线小角度衍射法、气体吸附法、电子显微镜观察法等.重点介绍了这些表征方法对多孔材料的孔道有序性、孔形态、比表面积和孔体积及孔径等的表征分析应用,最后简单介绍了孔结构表征的新方法.     

New opportunities for 3D materials science of polycrystalline materials at the micrometre lengthscale by combined use of X-ray diffraction and X-ray imaging

Non-destructive, three-dimensional (3D) characterization of the grain structure in mono-phase polycrystalline materials is an open challenge in material science. Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting possibilities for mapping 3D grain shapes and crystallographic orientations for certain categories of polycrystalline materials. Direct visualisation of the three-dimensional grain boundary network or of two-phase (duplex) grain structures by means of absorption and/or phase contrast techniques may be possible, but is restricted to specific material systems. A recent extension of this methodology, termed X-ray diffraction contrast tomography (DCT), combines the principles of X-ray diffraction imaging, three-dimensional X-ray diffraction microscopy (3DXRD) and image reconstruction from projections. DCT provides simultaneous access to 3D grain shape, crystallographic orientation and local attenuation coefficient distribution. The technique applies to the larger range of plastically undeformed, polycrystalline mono-phase materials, provided some conditions on grain size and texture are fulfilled. The straightforward combination with high-resolution microtomography opens interesting new possibilities for the observation of microstructure related damage and deformation mechanisms in these materials.     

基于FIB的三维表征分析技术及应用进展

聚焦离子束技术凭借其独特的微纳尺度制造能力和优势,已成为纳米科技工作者不可或缺的工具之一。随着新型FIB硬件设备的多功能化,FIB三维表征技术的不断完善,使FIB三维表征技术在材料研究领域的应用更加广泛和深入。与其他三维表征技术相比,FIB三维表征技术具有控制精度高、分析微观区域大、分辨率高等特点。FIB技术与SIMS、SEM、EDX、EBSD等系统的结合,可对不同材料进行三维空间状态下的形貌、成分、取向等信息的分析。文章简要概述了3D-SIMS、3D．Imaging／EDX、3D—EBSDg种基于FIB的三维表征技术,具体包括FIB三维表征技术的成像一切割的原理及过程。综述了几种不同表征手段在各种材料中的应用和发展。最后指出FIB三维表征技术在应用中的一些不足并对该技术发展方向进行了展望。     

3维打印用聚乳酸材料的改性研究进展

聚乳酸材料具有环保可生物降解性的优点,故其经常作为3维(3D)打印的原材料使用,然而其自身的脆性大、玻璃化温度低和热稳定性差等缺点,限制了该类材料的进一步应用和推广。所以对聚乳酸进行改性研究,改善它的力学性能或者耐热性能,从而扩大其在3D打印领域的应用具有很重要的研究意义。综述了聚乳酸材料的改性方法以及相关研究进展,主要从物理改性和化学改性等两类改性方法来分析聚乳酸改性的研究现状,总结分析了两类改性方法面临的问题并展望其前景,还对改性后的聚乳酸材料的应用进展进行总结与展望。     

Current status of 4D printing technology and the potential of light-reactive smart materials as 4D printable materials

The onset of multi-material 3D printing and the combination of smart materials into the printable material has led to the development of an exciting new technology called 4D printing. This paper will introduce the background and development into 4D printing, discuss water reactive 4D printing methods and temperature reactive 4D printing, modelling and simulation software, and future applications of this new technology. Smart materials that react to different external stimuli are described, along with the benefits of these smart materials and their potential use in 4D printing applications; specifically, existing light-reactive smart materials. 4D printing has the prospective to simplify the design and manufacturing of different products and the potential of automating actuation devices that naturally react to their environment without the need for human interaction, batteries, processors, sensors, and motors.     

From Flatland to Spaceland: Higher Dimensional Patterning with Two‐Dimensional Materials

The creation of three‐dimensional (3D) structures from two‐dimensional (2D) nanomaterial building blocks enables novel chemical, mechanical or physical functionalities that cannot be realized with planar thin films or in bulk materials. Here, we review the use of emerging 2D materials to create complex out‐of‐plane surface topographies and 3D material architectures. We focus on recent approaches that yield periodic textures or patterns, and present four techniques as case studies: (i) wrinkling and crumpling of planar sheets, (ii) encapsulation by crumpled nanosheet shells, (iii) origami folding and kirigami cutting to create programmed curvature, and (iv) 3D printing of 2D material suspensions. Work to date in this field has primarily used graphene and graphene oxide as the 2D building blocks, and we consider how these unconventional approaches may be extended to alternative 2D materials and their heterostructures. Taken together, these emerging patterning and texturing techniques represent an intriguing alternative to conventional materials synthesis and processing methods, and are expected to contribute to the development of new composites, stretchable electronics, energy storage devices, chemical barriers, and biomaterials.     

Three‐Dimensional Printing of Multifunctional Nanocomposites: Manufacturing Techniques and Applications

The integration of nanotechnology into three‐dimensional printing (3DP) offers huge potential and opportunities for the manufacturing of 3D engineered materials exhibiting optimized properties and multifunctionality. The literature relating to different 3DP techniques used to fabricate 3D structures at the macro‐ and microscale made of nanocomposite materials is reviewed here. The current state‐of‐the‐art fabrication methods, their main characteristics (e.g., resolutions, advantages, limitations), the process parameters, and materials requirements are discussed. A comprehensive review is carried out on the use of metal‐ and carbon‐based nanomaterials incorporated into polymers or hydrogels for the manufacturing of 3D structures, mostly at the microscale, using different 3D‐printing techniques. Several methods, including but not limited to micro‐stereolithography, extrusion‐based direct‐write technologies, inkjet‐printing techniques, and popular powder‐bed technology, are discussed. Various examples of 3D nanocomposite macro‐ and microstructures manufactured using different 3D‐printing technologies for a wide range of domains such as microelectromechanical systems (MEMS), lab‐on‐a‐chip, microfluidics, engineered materials and composites, microelectronics, tissue engineering, and biosystems are reviewed. Parallel advances on materials and techniques are still required in order to employ the full potential of 3D printing of multifunctional nanocomposites.     

Modeling strategies of 3D woven composites: A review

Due to advancements made in 3D weaving process, 3D woven composites have evolved as an attractive structural material for multi-directional load bearing and impact applications, due to their unique transverse properties such as stiffness, strength, fracture toughness and damage resistance. Substantial progress has been made in recent years for the development of new modeling techniques in design and analysis to understand the unique mechanical behavior of 3D woven composites. This paper systematically reviews the modeling techniques along with their capabilities and limitations for characterization of the micro-geometry, mechanical/thermo-mechanical behavior and impact behavior of 3D woven composites. Advantages, disadvantages and applications of 3D woven composites have also been delineated. In addition, this reference list provides a good database for future research on 3D woven composites.     

材料前沿测试表征技术及其在船舶材料领域的应用展望

材料测试表征技术是了解材料宏观和微观特征、剖析材料科学问题、进行材料应用评价的基础,测试表征技术的发展极大地加速了材料科学重大发现和重要理论创新的进程,密切跟踪测试表征技术前沿动态并尝试在科研生产中加以运用是材料研究的主要创新途径。通过了解材料基础研究和工程应用所关注的关键性能特征(如力学性能、化学成分、微观特征、疲劳性能、腐蚀性能等)的测试表征技术的发展现状,并分析前沿测试表征技术在船舶材料中的应用前景,为船舶领域的材料研制和工程应用研究提供参考。     

3D printing with particles as feedstock materials

3D printing has been applied in numerous research fields ranging from biomedical, mechanical engineering and chemistry to material science. 3D printing applications have driven innovations in particle technology, especially through tackling particle-related issues arising from the development of particle-based printing feedstocks across such application areas. Therefore, in this review, established 3D printing processes are described to include their prototyping mechanisms, advantages and limitations. Various particulate systems, including dry and wet systems, as printing feedstock materials are introduced. The main motivation for this paper is to outline the current state of particulate feedstock systems and to attempt to outline future directions for enhancing these particle applications. This paper would be valuable for individuals, researchers and companies who need adequate and comparative information regarding the state of particle applications in the AM industry.     

Intercalation of Layered Materials from Bulk to 2D

Intercalation in few‐layer (2D) materials is a rapidly growing area of research to develop next‐generation energy‐storage and optoelectronic devices, including batteries, sensors, transistors, and electrically tunable displays. Identifying fundamental differences between intercalation in bulk and 2D materials will play a key role in developing functional devices. Herein, advances in few‐layer intercalation are addressed in the historical context of bulk intercalation. First, synthesis methods and structural properties are discussed, emphasizing electrochemical techniques, the mechanism of intercalation, and the formation of a solid‐electrolyte interphase. To address fundamental differences between bulk and 2D materials, scaling relationships describe how intercalation kinetics, structure, and electronic and optical properties depend on material thickness and lateral dimension. Here, diffusion rates, pseudocapacity, limits of staging, and electronic structure are compared for bulk and 2D materials. Next, the optoelectronic properties are summarized, focusing on charge transfer, conductivity, and electronic structure. For energy devices, opportunities also emerge to design van der Waals heterostructures with high capacities and excellent cycling performance. Initial studies of heterostructured electrodes are compared to state‐of‐the‐art battery materials. Finally, challenges and opportunities are presented for 2D materials in energy and optoelectronic applications, along with promising research directions in synthesis and characterization to engineer 2D materials for superior devices.