Shuai Wang Koichi Tsuchiya Lei Wang Minoru Umemoto
材料科学技术（英）
The deformed microstructures of a TiNi shape memory alloy were investigated in present study to clarify the deformation mechanism. It is found that the stress-strain curve was divided into three stages based on the deformation modes. The cause of martensitic stabilization effect was also interpreted by paying special attention to the deformed microstructures. Transmission electron microscopic examination revealed that at the early stage of deformation martensitic reorientation and compound twinning relieved some of the elastic strain energy stored in martensite, and this contributes to the martensitic stabilization effect. However, when deformation strain became larger, the density of dislocations increased correspondingly. Antiphase boundaries were also found. The degree of ordering was therefore decreased due to dislocations and antiphase boundaries.
So disordering was another cause of martensitic stabilization e®ect. In the middle stage of deformation martensitic stabilization was attributed to the two reasons above.
关键词:
TiNi shape memory alloy
,
transmission electron microscopy
,
ordering
,
dislocation
,
martensitic transformation.
张福勤
,
黄启忠
,
邹林华
,
黄伯云
,
熊翔
,
张传福
无机材料学报
采用TEM表征结构、喇曼光谱表征石墨化度,研究了C/C复合材料中典型粗糙层(RL)和光滑层(SL)结构热解炭生长特征及其与可石墨化性之间的对应关系.结果表明,RL为层状结构,片层呈平直形状,有明显的锥状生长特征,同一锥面中石墨微晶c轴的取向基本相同,相邻锥面中的相差一个小角度,SL没有明显的生长特征;RL比SL结构热解炭容易石墨化,经2400℃石墨化处理后,两者(002)衍射弧宽度分别为39°和66°,对应的石墨化度分别为87.6％和25.6％.提出了一种RL结构热解炭锥状生长结构模型.
关键词:
热解炭
,
transmission electron microscopy
,
Raman spectroscopy
,
structure
卢焕明
,
叶志镇
,
黄靖云
,
汪雷
,
赵炳辉
无机材料学报
利用透射电子显微镜及X射线衍射,研究脉冲激光沉积技术(PLD)在Si(001)衬底上生长LiNbO3薄膜的微结构.结果表明,在600℃的衬底温度、30Pa的氧分压条件下,在硅片表面5nm厚的非晶氧化层上生长的薄膜,为c轴择优取向的单相LiNbO3晶体.本文还讨论了获得c轴择优取向LiNbO3薄膜的生长机理.
关键词:
LiNbO3薄膜
,
transmission electron microscopy
,
pulsed laser deposition
夏校良
,
郑轶
,
于砚廷
,
李晔
,
欧阳家虎
稀有金属材料与工程
采用X射线衍射、高分辨透射电镜、选区电子衍射以及拉曼光谱等技术手段研究了(Sm0.6Y0.4)2Zr2O7陶瓷的晶体结构.X射线衍射表明,(Sm0.6Y0.4)2Zr2O7陶瓷为单一立方相缺陷型萤石结构.然而高分辨电镜和选区电子衍射观察结果显示,在电子衍射花样中除了缺陷型萤石相点阵的衍射外,还发现有对应于烧绿石相的弱散射斑点.这表明在无序的缺陷型萤石相点阵中存在短程有序化现象.拉曼光谱结果进一步证实了在微米或纳米尺度范围内存在短程有序化现象.
关键词:
萤石
,
无序
,
短程有序化
,
透射电镜
,
拉曼光谱
段杨杨
,
王昕
,
高凡
材料开发与应用
本文利用阴离子模板法第一次制得杆状形貌的介孔二氧化硅材料.搅拌速度影响无机硅源的聚合速度及表面活性剂分子、助结构导向剂分子及无机硅源的自组装,从而影响所得样品的形貌.在200 rpm和1000 rpm下分别制得杆状(或手性棒状)和球形的介孔二氧化硅材料.并通过透射电子显微镜(TEM)对其形貌进行了表征.
关键词:
搅拌速度
,
形貌
,
介孔二氧化硅
,
透射电子显微镜
