文献类型：期刊文献

中文题名：微观力学表征技术的发展及其在木材科学领域中的应用

英文题名：Development of Micromechanical Technique and Application on Wood Science

作者：林兰英[1] 秦理哲[1] 傅峰[1]

第一作者：林兰英

机构：[1]中国林业科学研究院木材工业研究所国家林业局木材科学与技术重点实验室,北京100091

年份：2015

卷号：51

期号：2

起止页码：121-128

中文期刊名：林业科学

外文期刊名：Scientia Silvae Sinicae

收录：CSTPCD;;Scopus;北大核心:【北大核心2014】；CSCD:【CSCD2015_2016】；

基金：国家自然科学基金项目“木材胶合界面微结构复合效应与影响机制”(31370012)

语种：中文

中文关键词：微观力学;木材;木基复合材料;细胞壁;界面

外文关键词：micromechanical; wood; wood-based composites; cell wall; interface

分类号：S781.2

摘要：微观力学表征技术是表征材料微纳米力学性能的重要技术手段,目前已被广泛用于表征材料的超微构造和解析材料的力学行为。随着材料科学研究尺度缩小,微观力学表征技术逐步从纳米向超纳米、从分子向超分子甚至粒子水平发展。按照试样信息的不同方式,微观力学表征技术主要包括纳米力学测试技术(探针技术)和超纳米力学测试技术(显微镜技术);其中,纳米力学测试技术包括准静态纳米压痕技术、动态纳米压痕技术和动态模量成像技术,超纳米力学测试技术包括原子力显微镜技术和基于原子力显微镜技术的新型微观力学表征技术。木材是一种多孔状、层次状、各向异性的非均质天然高分子复合材料,其超微结构是细胞壁由不同厚度的层次组成。细胞壁是决定木材和木质纤维材料性能的主要因素,是木材的实质承载结构;细胞壁的力学性能是由壁层结构、化学组成的分布与结合方式决定的。开展木材和改性木材细胞壁纳观尺度的力学性能、分布及影响对实现木基复合材料的高效设计具有重要意义。自Wimmer等首次将纳米压痕技术应用于天然木材细胞壁微观力学后,国内外学者主要采取准静态纳米压痕测量技术和动态纳米压痕测量技术对不同树种木材以及化学改性和生物改性木材细胞壁的硬度、弹性模量、蠕变特性与黏弹性等力学性能进行了研究。木质材料界面作为纳米级厚度的界面相或者界面层,不仅影响木质材料的强度、刚度,而且影响木质材料的断裂韧性等。界面力学是决定木基复合材料整体力学性质的关键,是引起材料变形、强度下降的主要原因。研究界面的属性和特征对于木基复合材料整体属性的评价以及结构的优化设计有一定参考价值,研究内容涉及有胶合界面、纤维增强聚合物界面以及木制品涂层的微观力学。随着研究尺度逐渐缩小,微观力学表征技术趋向高分辨率及数据定量化,如今已能在纳米级分辨率下进行力学信息成像,为木材科学领域的研究提供了方便。微观力学表征技术在木材科学领域中的应用尚具有较大潜力,但仍有较多方向尚未涉及,还应在以下3方面展开研究:一是需要开展微观力学技术在木材科学领域应用的标准化研究,规范测试过程,确保测试结果的可靠性和一致性;二是建立木质材料宏观到微观的完整力学体系,从本质上剖析木质材料的力学行为,在纳米尺度上表征木质材料的性质和失效机制;三是随着木材科学领域研究的深入,需建立微观力学与微观化学、微观物理、微观环境学的联系,丰富木材及木基复合材料在微纳尺度的研究。
As an important method to measure the micro and nano mechanical properties of materials, micromechanical characterization technique has been already extensively used to study the ultrastrueture and mechanical behavior of materials. With the development of characterization technique, research scale shrank tremendously from nano to ultra-nano scale, from molecular to super-molecular scale, even to particle scale. Micromechanical characterization technique can be classified into two types according to the specimen information： nano mechanical testing technique （probe technique） and uhra-nano mechanical testing technique （ microscopy techniques）. The nano mechanical testing technique included quasi- static nanoindentation, dynamic nanoindentation and dynamic modulus imaging. The ultra-nano mechanical testing technique included atomic force microscopy （AFM） and new techniques based on AFM. Wood is a porous and layered heterogeneous anisotropic natural polymer. It is composed of layers with varying thickness. Cell wall is a central factor determining the properties of wood and wood fiber materials. It is also the essential stressed structure of wood. The mechanical properties of wood cell are depended on the wall layer structure,distribution and combination of chemical compositions. Researching the nano mechanical properties,distribution and affection of cell walls is critical for effective designing of wood and modified wood. Since nanoindentation was first successfully applied in wood cells of nature wood by Wimmer and his colleagues,scholars at home and abroad had generally adopted quasi-static nanoindentation and dynamic nanoindentation to study the nano mechanical properties of cell walls,such as hardness,modulus,creep properties, viscoelasticity,etc. As an interfacial layer or an interfacial phase with nano-scale thickness,the interfaces of wood materials impact their strength,stiffness and fracture toughness. Interfacial mechanics are the key of the whole mechanical properties of wood-based composites. They are also major causes of deformation and strength descent. The researches of the attributes and characteristics of interface are of great value of property evaluating and design optimizing of wood-based composites. The main researches in wood science field included bonding interface,interface of fiber reinforced polymers and micromechanics of coating over the woodworks. Micromechanical characterization technique was tending to high resolution and quantitative evaluation with researching scale shrinking, and already can be performed mechanical information imaging with nano resolution. Development of micromechanical characterization technique can provide great convenience for wood science research. However,tremendous room is needed for improvement. In the future,we should focus on the following three topics： Firstly,to conduct micromechanical technique standardization research,specify testing process and to ensure testing results consistency and reliability. Secondly,to establish relatively complete mechanical system from macrocosm to microcosm,and to further dissect mechanical behavior and failure mechanisms. Thirdly,to build the micro coupling techniques between mechanical,chemical,physical and environmental,so as to enrich the study of wood and wood-based composites at nano scale.