Jingchuan ZHU
,
Zhongda YIN and Zhonghong LAI(Dept. of Metals and Technology
,
Harbin Institute of Technology
,
Harbin
,
150001. China)
材料科学技术（英）
The fabrication. microstructure and mechanical properties of ZrO2-Ni functionally gradient materials (FGM ) have been studied. FGM as well as non-FG M of ZrO2-Ni system was developed by powder metallurgical process. X-ray diffractometer (XRD ). electron probe microanalyzer (EPMA), scanning electron microscope (SEM ) and optical microscope were employed to investigate the crystalline phases. chemical composition and microstructure Experimental results demonstrate that the composition and microstructure of ZrO2-Ni FGM have the expected gradient distribution. There are no distinct interfaces in the FGM due to the gradient change of components. that is, the constituents are continuous in microstructure everywhere. Moreover, Vickers hardness and flexural strength were measured for the common composites as a function of composition. It is made clear that the mechanical properties of the FGM vary corresponding to the constitutional changes as well
关键词:
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
LIU Xianghua
钢铁研究学报(英文版)
Rolling of gauge changeable (RGC) is a new technology to produce flat with different thickness (FDT), which could be used to replace conventional flat products in order to save metals and reduce structure weight. This paper introduced the method of RGC, investigated new problems in rolling theory of RGC, proposed the new formulas for caluclating parameters of RGC, and described some results of numerical simulation by FEM. As example, the products applications of FDT in bridge construction, ship building and auto manufacturing were presented. Finally the prospect for RGC and FDT was discussed.
关键词:
variable gauge rolling;longitudinal profile plate;tailor rolled blank
Materials and Corrosion-Werkstoffe Und Korrosion
The changes of corrosion potential (E-corr) of metals immersed in seawater were investigated with electrochemical technology and epifluoresence microscopy. In natural seawater, changes of E-corr were determined by the surface corrosion state of the metal. E-corr of passive metals exposed to natural seawater shifted to noble direction for about 150 mV in one day and it didn't change in sterile seawater. The in-situ observation showed that biofilms settled on the surfaces of passive metals when E-corr moved in noble direction. The bacteria number increased on the metal surface according to exponential law and it was in the same way with the ennoblement of E-corr. The attachment of bacteria during the initial period played an important role in the ennoblement of E-corr and it is believed that the carbohydrate and protein in the biofilm are reasons for this phenomenon. The double layer capacitance (C-dl) of passive metals decreased with time when immersed in natural seawater, while remained almost unchanged in sterile seawater. The increased thickness and reduced dielectric constant of C-dl may be reasons.
关键词:
stainless-steels;diminution;reduction;oxygen
X.L. Tian C.W. Zhan J.X. Hou X.C. Chen J.J. Sun
材料科学技术（英）
A nanocrystal model for liquid metals and amorphous metals has been developed. With the nanocrystal model, the broadening peak profiles (BPPs) of Cu, Al, Al65Cu20Fe15 alloy, Cu70Ni30 alloy and Fe50Si50 alloy were gained by broadening the X-ray diffraction (XRD) peaks of a crystal lattice. By comparing the BPPs with the XRD intensity curves measured on the liquid metals, it is found that the BPPs are closely in agreement with the XRD intensity curves, respectively, except the Fe50Si50 alloy. Therefore, the nanocrystal model can be used to determine if the atomic cluster structure of the liquid metal is similar to the structure of its crystal lattice.
关键词:
Liquid metal
,
Atomic Cluster
,
Structure
,
Crystal Lattice
D.Eylon
,
S.R.Seagle
材料科学技术（英）
The state of Ti research, development and industry is reviewed in this article. The fifty-year anniversary of Ti technology commercialization in the USA provides an opportunity for a historical perspective. Incorporation of "information-age" tools into alloy development, processing, and production invigorates the technology. Consolidation, diversification and globalization have been transforming the Ti industry in the recent years.
关键词:
B.Q. Li
材料科学技术（英）
Inherent twinnability of face-centered-cubic (fcc) metals was analyzed based on the direct competition between twinning partial dislocation nucleation and trailing partial dislocation nucleation, with which the twinnability of fcc metals can be simply expressed as function of the stacking-fault energy, the unstable stacking-fault energy, and the unstable twinning-fault energy of fcc metals. The predicted twinnability ranking matched well with former experimental results and provided a physical insight to understand twinnability from crystallographic orientation and fault energy parameters.
关键词:
Deformation twinning
