Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing
By cyclically deforming a [(5) over bar 913]perpendicular to[(5) over bar 79] copper bicrystal with a perpendicular grain boundary (GB), the fatigue crack initiation and fracture behavior were investigated. It was found that only the primary slip systems were activated on both G1[(5) over bar 913] and G2[(5) over bar 79] grains including the vicinity of the GB at axial plastic strain range of 1.8 x 10(-4)-2.56 x 10(-3). By observing the surface and fractography, it was confirmed that the fatigue cracks always nucleated and propagated along the GB, and displayed an obvious tendency on different surfaces. On the front surface of the bicrystal, the intergranular cracking was more preferential than that on the lateral surface, even though the geometrical conditions among PSB, GB and stress axis on the lateral surface claimed to enhance cracking are more close to those proposed by Christ (Mater. Sci. Eng. A117 (1989) L25). Based on the experimental results above, the effect of the interaction of PSB with GB and stress axis on intergranular fatigue cracking in the bicrystal is discussed. It is suggested that Christ's geometrical conditions for intergranular cracking might be further developed and the plastic strain incompatibility near the GB should play a more important effect on intergranular fatigue cracking. (C) 1999 Elsevier Science S.A. All rights reserved.
关键词:
copper bicrystal;cyclic deformation;grain boundary;fractography;intergranular cracking;nucleation
Composites Science and Technology
Short glass fiber-reinforced nylon 6,6 with and without rubbery inclusions were injection molded into standard specimens. The mechanical properties and the residual fiber length distribution were measured. The macro-to-micro model proposed by Bowyer and Bader [J. Mater. Sci., 7 (1972) 1315] was used to determine the interfacial shear strength (IFSS). The IFSS in the toughened nylon 6,6-based composites was found to be superior to that in the untoughened nylon 6,6-based composites. This indicates that the presence of rubbery phase in the composite system contributed to the interfacial bonding between nylon 6,6 and glass fibers (GF). Back-scattered electron imaging taken on a plane perpendicular to the mold filling direction for fiber-reinforced toughened nylon 6,6 showed that the rubbery phase adhered to the GF surface. This morphological feature was regarded as a main factor responsible for the improvement of IFSS in the reinforced toughened nylon 6,6 composites. (C) 2004 Published by Elsevier Ltd.
关键词:
glass fiber;nylon 6,6;reinforced polymers;glass;strength;behavior;microstructures;thermoplastics
杨金瑞
,
余尚先
,
顾江楠
高分子材料科学与工程
通过对resol(羟甲基酚化合物和低分子量羟甲基酚树脂)DEPT135图谱的分析讨论,得到一系列计算resol微细结构参数的经验公式.根据DEPT135图谱可判断是否发生缩聚反应,根据经验公式可计算酚单体各个活性点参与反应百分率或酚羟基导入率、不同类型缩聚所占百分率及低分子量羟甲基酚树脂的平均核体数.
关键词:
羟甲基酚化合物
,
羟甲基酚树脂
,
DEPT135
,
结构参数
中国腐蚀与防护学报
由中国金属学会主办、中国科学院金属研究所承办的英文期刊ActaMetallurgicaSinica（EnglishLettersl于近日通过ThomsonReuters的评审，入选SCI数据库。该刊自2009年起出版的论文被ThomsonReuters旗下的ScienceCitationIndexExpanded（alsoknownasSeiSeareh），JournalCitationReports／ScienceEdition和CurrentContents@／EngineeringComputingandTechnol-ogy所收录。这是继（《金属学报》和《材料科学技术（英文版）》之后，金属所承办的又一被SCI收录的期刊。
关键词:
SCI
,
中国科学院金属研究所
,
中国金属学会
,
英文期刊
,
材料科学技术
,
数据库
中国腐蚀与防护学报
由中国金属学会主办、中国科学院金属研究所承办的英文期刊ActaMetallurgicaSinica（EnglishLettersl于近日通过ThomsonReuters的评审，入选SCI数据库。该刊自2009年起出版的论文被ThomsonReuters旗下的ScienceCitationIndexExpanded（alsoknownasSeiSeareh），JournalCitationReports／ScienceEdition和CurrentContents@／EngineeringComputingandTechnol-ogy所收录。这是继（《金属学报》和《材料科学技术（英文版）》之后，金属所承办的又一被SCI收录的期刊。
关键词:
SCI
,
中国科学院金属研究所
,
中国金属学会
,
英文期刊
,
材料科学技术
,
数据库
ZHANG Lei WANG Peixuan TAO Rong MA Ruzhang ZHANG Guoguang University of Science and Technology Beijing
,
Beijing
,
China professor
,
Department of Materials Physics.University of Science and Technology Beijing.Beijing 100083
,
China
金属学报(英文版)
Nucleation and growth of He bubbles at different annealing temperatures T≤1023 K in stain- less steels HR-2 and SS321,implanted with He~+(40-70 keV.1×10~(16)-6× 10~(17) He~+/cm~2),were ohserved under TEM.T=0.45T_m seems to be a transition temperature.The He bubbles continue mainly their nucleation at 0.3T_m< T<0.45T_m,and grow predominantly at T≥0.45T_m,due probably to migration and coalescence by surface diffusion of metal atoms around the bubbles.The apparent activation energies for the growth are found to he 0.41 and 0.31 eV for HR-2 and SS321 respectively.The bubble density in HR-2 is greater than that in SS321 within whole measuring temperature range,and the onset temperature of rapid swelling is also higher.It is believed that the resistance of HR-2 to He is superior to that fo SS321.
关键词:
stainless steel
,
null
,
null
,
null
,
null
Physica E-Low-Dimensional Systems & Nanostructures
Generally, phase transfer of metal nanoparticles between aqueous phase and organic phase need two reagents at last. One is stabilizer of nanoparticles, the other is phase-transfer agent (Chem. Lett. 21 (1992) 1527; J. Colloid Interface Sci. 161 (1993) 471; J. Phys. Chem B 101 (1997) 9876; Chem. Commun. (1997) 537; Langmuir 14 (1998) 602; J. Phys. Chem B 103 (1999) 7238; Chem. Mater. 13 (2001) 4692; Langmuir 17 (2001) 733; Langmuir 16 (2000) 9775; Langmuir 18 (2002) 3364; J. Am. Chem. Soc. 123 (12001) 11148). In this paper, Ag nanoparticle prepared by tannic acid reduction of AgNO3 in aqueous medium were transferred to chloroform solution via a remarkably simple one-step route under the effect of phase-transfer inducer dimethyldioctadecylammonium chloride (DDAC), where no special stabilizer was required. Monolayer of Ag nanoparticles is obtained on carbon film by self-assembly using chloroform organosol. The effect of the inducer DDAC concentration is checked, and it was found that 5 x 10(-3) mol dm(-3) of DDAC was the optimum concentration for phase transfer of Ag nanoparticles. The organosol, Ag nanoparticle self-assembled monolayer and phase transfer were characterized by UV-vis spectra, TEM, ED and TF-IR. (C) 2004 Elsevier B.V. All rights reserved.
关键词:
silver;nanostructures;UV-Vis spectroscopy;DDAC;organosol;modified gold nanoparticles;shape-controlled synthesis;silver;nanoparticles;colloidal gold;aspect-ratio;nanorods;toluene;nanodisks;platinum;water
腐蚀学报（英文）
由中国金属学会主办、中国科学院金属研究所承办的英文期刊Acta Metallurgica Sinica（English Letters）于近日通过Thomson Reuters的评审，入选SCI数据库．该刊自2009年起出版的论文被Thomson Reuters旗下的Science Citation Index Expanded（alsoknownas Sci Search），Journal Citation Reports／science Edition和Current Contents/Engineering Computingand Technology所收录．这是继《金属学报》和《材料科学技术（英文版）》之后，金属所承办的又一被SCI收录的期刊
关键词:
SCI
,
中国科学院金属研究所
,
Thomson
,
中国金属学会
,
Edition
,
英文期刊
,
材料科学技术
,
数据库
李悦
,
邓爱红
,
刘莉
,
王康
,
谢莎
材料研究学报
利用x射线衍射(xRD)和慢正电子束分析(SPBA)技术研究高温退火后含He钛膜的微观结构和钛膜内He相关缺陷的演化.XRD分析表明,高温退火后Ti和Si在高温下发生反应形成稳定的多晶TiSi2化合物,He原子的掺入会影响TiSi2晶体的择优取向,而对TiSi2晶粒尺寸的影响较小.SPBA结果表明,室温下,钛膜内的缺陷浓度或尺寸会随着掺He浓度的增加而增大;高温退火后,当He浓度小于5％(原子分数,下同)时(除2％外),钛膜内的He相关缺陷浓度随着He浓度增加相应地增加.当He浓度增加到14％时,高温会使较高浓度的He原子、He-空位复合体以及小He泡迁移聚集形成一些尺寸较大He泡,而较大He泡周围与He相关的小尺寸缺陷的浓度则会发生相应地减少.
关键词:
金属材料
,
含He钛膜
,
直流磁控溅射
,
He相关缺陷
,
XRD
,
SPBA
