Feng Yan
材料科学技术（英文）
A polycrystalline Cu of 99.995% purity has been deformed by dynamic plastic deformation at liquid nitrogen temperature to a strain of 2.1 (LNT-DPD Cu). Three distinct regions that are dominated by dislocation slip, shear banding and nanotwinning, form a multi-component nanostructure. The microstructure of each region has been quantified by transmission electron microscopy assisted by Kikuchi line analysis. Based on the structural parameters the stored energy of each region was evaluated, and the total energy can be assumed to be a linear additivity of that in each region weighted by the respective volume fraction. A microstructure based evaluation of the stored energy of multi-component nanostructure has been proposed.
关键词:
Stored energy
Hongwang YANG
,
Xinchun CHANG
,
Wanliang HOU
,
Jianqiang WANG
材料科学技术（英文）
Transmission electron microscopy (TEM) is usually used to identify the amorphicity. However, some artifacts may be introduced due to improper TEM foil preparation. In this paper, three Al-rich metallic glasses with and without a glass transition were selected for characterizing the effect of the electropolishing condition on the as-quenched structure during TEM specimen preparation. It is shown that the occurrence of the modulated bright-dark structure under TEM observation is closely sensitive to the electropolishing condition, which suggests us being careful about the possible artifacts induced by specimen preparation when examining amorphous alloys under TEM.
关键词:
Al-based amorphous alloy
,
null
,
null
冯尚蕾
,
杨迎国
,
白朔
,
许力
,
杨新梅
,
夏汇浩
,
周兴泰
新型炭材料
采用化学气相沉积技术，以甲烷作为碳源，在核石墨IG-110基体上制备层状热解炭涂层。利用偏光显微镜、扫描电子显微镜( SEM)、透射电子显微镜( TEM)以及同步辐射掠入射X 射线衍射( GI-XRD)研究热解炭涂层的微观结构和生长特性。结果表明，热解炭涂层具有大锥体、小锥体和再生锥体三种生长锥微观结构，热解炭片层间结合紧密，生长锥间结合密实。热解炭涂层存在光滑层和再生层两种织构，每种织构都含有两种晶面间距不同的相结构，平滑层主要含有低石墨化度相，而再生层主要含有高石墨化度相。热解炭涂层致密的微观结构和仅存在的纳米级别的微孔使其可以作为气体阻隔涂层。
关键词:
热解炭
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微观结构
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透射电子显微镜
,
同步辐射掠入射X 射线衍射
王俊山
,
李仲平
,
敖明
,
许正辉
,
刘朗
,
胡子君
,
彭维周
新型炭材料
doi:10.3969/j.issn.1007-8827.2006.02.002
利用SEM和TEM考察了3D C/C复合材料在电弧加热器上烧蚀后的材料表层显微组织结构变化.发现炭纤维和基体炭中的石墨微晶经过烧蚀后都得到了明显的发展.在距烧蚀表面几个纳米的深度范围内形成了高度取向的带状石墨织构,同时,在带状织构中间也形成了许多孔洞和缝隙.在距烧蚀表面几个微米的深度形成了卷曲柱状结构,在这些柱状结构周围有许多缺陷.在纤维和基体炭的界面区域,靠近纤维一侧形成了带状织构,且织构间的缝隙变大.
关键词:
C/C复合材料
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扫描电子显微镜
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透射电子显微镜
,
织构
郭领军
,
彭坚
新型炭材料
doi:10.1016/S1872-5805(17)60115-X
采用无催化剂乙炔火焰合成法在碳化钨基板上制备出石墨烯片,所制备的石墨烯片呈花瓣状均匀地垂直生长在副产物-炭微粒上,呈现出花状形貌.实验过程中,乙炔剧烈燃烧产生高温及高压环境,加速了未完全燃烧乙炔的裂解及自由碳基团的环化反应,直接在气相环境中合成了石墨烯微晶片,部分石墨烯微晶片会卷曲成炭黑晶核,炭黑晶核会继续吸附石墨烯微晶片生长为炭微粒.但是,在反应装置的作用下,携带石墨烯微晶片以及炭黑晶核的燃气流会在基体表面形成湍流和逆流,打乱了石墨烯晶片被炭黑粒子吸附并包裹使之生长的过程,导致石墨烯微晶片垂直于炭微粒生长为花瓣状石墨烯片.
关键词:
石墨烯
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火焰合成法
,
微观结构
,
透射电子显微镜
,
拉曼光谱
