程小全
,
王进
,
ALI Al-Mansour
,
胡仁伟
,
关志东
复合材料学报
doi:10.3321/j.issn:1000-3851.2007.02.026
对含矩形边缘分层缺陷层合板的压缩性能进行试验研究和理论分析,考察了层合板厚度(含铺层形式)、分层位置、形状、面积以及环境等因素对压缩强度的影响,并采用分层扩展以及软化夹杂两种模型对含分层层合板的压缩强度进行了计算和破坏机理分析.结果表明:厚板对边缘分层缺陷不敏感,中等厚度和薄层合板比较敏感;缺陷的位置和形状对层合板压缩强度有一定的影响;湿热环境改变了含缺陷板的压缩破坏机理,并对中等厚度板和薄板的压缩强度有明显的影响.两种模型中软化夹杂模型效果较好,可用于工程设计计算.
关键词:
层合板
,
分层
,
缺陷
,
压缩强度
陈小庆
,
孙利杰
,
邬小鹏
,
钟泽
,
傅竹西
功能材料
用MOCVD方法在Si基片上生长了Al掺杂的SiC薄膜,发现三甲基铝(TMA)源载气流量与硅烷流量之比的大小,会决定薄膜的导电类型.用XPS方法测试样品后发现,TMA载气流量与硅烷流量比直接影响Al原子在SiC薄膜中的含量.Al含量在1.5%以下,Al原子在SiC薄膜中主要以填隙形式(Ali)存在,薄膜显示出n型;而Al含量在1.5%～3%之间的时候,Al原子主要以替位Si(AlSi)的形式存在,薄膜显示出p型.继续增加掺杂源的流量,所得SiC薄膜结晶质量会变得较差,电阻也变得较高.
关键词:
3C-SiC
,
SiC:Al
,
MOCVD
,
导电类型
Journal of Alloys and Compounds
Interdiffusion coefficients within the beta-phase region of the nickel-cobalt-chromium-aluminum (Ni-Co-Cr-Al) quaternary system were estimated by square root diffusivity analysis. The obtained results indicated that the cross interdiffusion coefficients D(ij) (i not equal j, i, j = Al, Cr, Co) other than D(AlCo), were less than the main interdiffusion coefficients Do (i = j), and that the values of D(Ali) were greater than those of D(Cri) and D(Coi). This finding suggests that the addition of chromium decreases the interdiffusion coefficients of aluminum and cobalt, but the addition of cobalt did not cause an obvious change in the interdiffusion coefficients of aluminum and chromium in the beta-phase region. The different effects associated with the additions of chromium and cobalt were qualitatively discussed in light of the relationship between the thermodynamic properties of the system and Wagner's interaction parameter. The results revealed that the different effects could be ascribed to the stronger thermodynamic interactions between aluminum and cobalt compared to that between aluminum and chromium. (C) 2009 Elsevier B.V. All rights reserved.
关键词:
Diffusion;NiAl phase;Electron microprobe;multicomponent diffusion couples;square root diffusivity;transfer-matrix method;zero-flux planes;intermetallic compound;coefficients;ternary;nickel;alloys;fe
鲜晓斌
,
刘柯钊
,
吕学超
,
张永彬
稀有金属材料与工程
用循环Ar+轰击-磁控溅射离子镀(MSIP)法在U表面上镀Al,Ti/Al,并采用俄歇电子能谱仪(AES)、扫描电镜(SEM)、电化学实验和平面磨耗实验,研究了其表面、剖面形貌和耐磨耐蚀性能,以及Al/U和Ti/Al镀层界面.结果表明:U上循环Ar+轰击-磁控溅射离子镀Al,Ti/Al界面存在较宽的原子共混区,且Ti/Al镀层的耐磨耐蚀性能明显优于单一磁控溅射离子镀Al层.
关键词:
Ti/Al镀层
,
界面
,
耐磨性
,
耐蚀性
Y.Ma
,
Y.Hao
,
S.Z.Kou
,
X.N.Lu
金属学报(英文版)
Based on the experiment and the thermodynamics analysis for CuO/Al system, it is founded that the compounding reaction of CuO/Al under low temperature is available. The general equation of adiabatic temperature of the system is set up, and the influence of resultant concentration and temperature on adiabatic temperature is theoretically analyzed. The values of heat effect of CuO/Al system under different temperature are also caculated.
关键词:
composite in situ
,
null
,
null
Hong TAO
,
Chengji DENG
,
Lianmeng ZHANG
,
Runzhang YUAN
材料科学技术（英文）
Al/Al2O3 composites of different ratios were hot-press sintered at 575 similar to 640℃ under a pressure of 30 MPa for 2 h in a vacuum furnace. It was found that the relative density of the Al/Al2O3 composites could be increased evidently with the rise of sinter temperature. No reaction occurred between Al and Al2O3 at the sinter temperatures. Under 640℃-30 MPa-2 h experimental condition, Al/Al2O3 system FGM was successfully fabricated, and its density range changed quasi-continuously from 2.887x10(3) kg/m(3) to 3.1909x10(3) kg/m3 within the middle 1.0 mm thickness range.
关键词:
YANG Wenying LU Fanxiu ZHANG Shouhua University of Science and Technology Beijing
,
Beijing
,
China Department of Materials Science and Engineering
,
University of Science and Technology Beijing
,
Beijing
,
100083
,
China
金属学报(英文版)
The “order-disorder” model was adopted to calculate the lattice vacancies related to the com- position change in Ni_3Al alloys.A great deal of vacancies,i.e.,the non-stoichiometric vacan- cies,may exist in the Ni_3Al alloys containing Al over stoichiometry,i.e.25 at.-%.This was confirmed by the positron annihilation technique.Therefore,the influence of Al content on the enhancing behaviour of B towards the ductility of Ni_3Al alloys can be understood by the interaction of non-stoiehiometric vacancies and B atoms.
关键词:
Intermetallic compounds
,
null
,
null
Lin GENG Congkai YAO Dept.of Metals and Technology
,
Harbin Institute of Technology (HIT)
,
Harbin
,
150006
,
China
材料科学技术（英文）
The microstructure of SiC whisker reinforced aluminium alloy (SiC_w/Al) composite is reviewed,and the SiC-Al interface in SiC_w/Al composite is especially discussed,The main contents are morphology of the aluminium matrix in SiC_w/Al composite;microstructures and defects of SiC whiskers in SiC_w/Al composite and bonding mechanisms of the SiC-Al interface in SiC_w/Al com- posite.
关键词:
silicon carbide
,
null
,
null
,
null
,
null
