W. Gao
,
T. Sakai and H. Miura( Department of Mechanical Engineering and Intelligent Systems
,
The University of Electro - Communica- tions
,
Chofu
,
Tokyo 182 - 8585
,
Japan)
金属学报(英文版)
An analytical model for dynamic recrystallization (DRX) is studied based on the relative grain size model proposed by Sakai and Jonas, and the characteristic flow behaviors under DRX are analyzed and simulated. Introducing the variation of dynamic grain size and the heterogeneous distribution of disolo- cation densities densities under DRX,a simple method for modeling and simulating DRX processes is developed by using Laplace transformation theory. The results derived from the present model agree well with the experimental results in literatures. This simulation can reproduce a number of features in DRX flow behaviors, for example,single and multiple peak flow behaviors followed by a steady state flow, the transition between them, and so on.
关键词:
dynamic recrystallization
,
null
,
null
,
null
Rsc Advances
With the verification of the existence of the dissolution-electrodeposition mechanism during the electro-reduction of solid silica in molten CaCl2, the present study not only provides direct scientific support for the controllable electrolytic extraction of nanostructured silicon in molten salts but it also opens an avenue to a continuous silicon extraction process via the electro-deposition of dissolved silicates in molten CaCl2. In addition, the present study increases the general understanding of the versatile material extraction route via the electro-deoxidization process of solid oxides in molten salts, which also provokes reconsiderations on the electrochemistry of insulating compounds.
关键词:
3-phase interlines;electrochemical preparation;insulator compounds;calcium-chloride;sio2 pellets;nanowires;electroreduction;dioxide;mechanism;titanium
Materials Letters
A simple and effective surface coating technique, electro-spark deposition (ESD), has been used to produce amorphous alloy coatings. Fe-Cr-Mo-Gd-C-B amorphous alloy rods produced by copper mould casting were used as electrode to produce coatings onto 304 stainless steel substrate. Classical X-ray diffraction (XRD), glancing angle XRD (GAXRD), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis indicate that the coatings have an average thickness of similar to 30 mu m, show an amorphous structure, and are metallurgically bonded to the substrate. Microhardness tests showed that the coating layer has a high hardness of 1542 kg/mm(2), implying a much improved wear resistance on surface of stainless steels. (c) 2006 Elsevier B.V. All rights reserved.
关键词:
bulk amorphous alloys;electro-spark deposition (ESD);coating;microhardness;wear;bulk metallic glasses;mechanical-properties;zr-ti;thickness;strength;behavior;mm
DAI Yongbin
,
YANG Weidong
,
WANG Shaofu
,
et al
钢铁研究学报(英文版)
This paper presents a new electro-hydraulic servo control method. This method introduces model predictive into generic model control (GMC). By receding optimization and makes feed-back correction, GMC performance is improved. Using improved weighted least square Support Vector Machines (WLS-SVM) to forecast and compensate the future sequence errors, the system’s precision and robust ness were increased. It elementary solved the systems delay, nonlinearity and time variability. The GMC based on improved WLS-SVM are applied to electro-hydraulic servo control system in hot mill. The result of a numerical simulation experiment shows the feasibility and effectiveness of this algorithm
关键词:
GMC;WLS-SVM;electro-hydraulic servo control system
P. He
金属学报(英文版)
The fuzzy numerical value analysis method is adopted for the first time, which solves the problem of nanometer electro-thermal in filming process. The key technique is embodied by controlling the time distribution, temperature and press in the filming process. The concrete technique of filming is showed by establishing the fuzzy mumbership function of above three indexes, which improves the precision of the materials of nanometer electro-thermal in hot-working. At the same time, the principles of the fuzzy relationship mapping inversion (FRMI) is put forward. Therefore, the standardization and continuity can be met.
关键词:
fuzzy control
,
null
,
null
Transactions of Nonferrous Metals Society of China
An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition. Epitaxial morphologies of the coating and its microstructural characteristics were investigated by means of SEM, XRD and TEM etc. It is observed that the fine column-like dendrites originated from the gamma'-particles or gamma'-clusters of the DS substrate and are un-continuously coarsened. The beta-phase particles precipitate and grow eutectically with the gamma-phase. The orientation of fine column dendrites depends on electro-spark deposition processing parameters and the microstructure can be characterized with superfine gamma and beta phases.
关键词:
electro-spark deposition;epitaxial growth;MCrAlY alloy;Ni-base;superalloy;coatings
Shijin ZHANG
,
Zhenfang LIAO
,
Changlin YANG
材料科学技术（英文）
On the basis of a great number of experiments, it is proved that the strength of concrete is improved greatly when it is mixed with activated water produced by the electro-hydraulic impulse. With the proper parameters, the compression strength of concrete can be increased by 45%. The reason for improvement of concrete strength by using activated water is discussed from the aspect of the structure of molecule.
关键词:
Concrete
,
null
,
null
Zhenfang LIAO
,
Shijin ZHANG
材料科学技术（英文）
Electro-hydraulic impulse water-air mixing jet by which the quality of metal materials can be improved is described in this paper. The experimental results proved that the hardness and the micro-hardness of the surface layer of metal materials can be improved with this method, for example, the microhardness of CrWMn can be increased by 35.62 percent.
关键词:
Electro-hydraulic impulse
,
null
,
null
Fenglei SHEN
,
Hongwei WANG
,
Dijiang WEN
材料科学技术（英文）
In this paper, diamond-like carbon (DLC) films were deposited on Ti alloy by electro-deposition. DLC films were brown and composed of the compact grains whose diameter was about 400 nm. Examined by XPS, the main composition of the films was carbon. In the Raman spectrum, there were a broad peak at 1350 cm-1 and a broad peak at 1600 cm-1, which indicated that the films were DLC films.
关键词:
Diamond-like carbon film
,
null
,
null
,
null
Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing
The objective of this work is to investigate the microstrain effect on grain growth and strain release processes in nanocrystalline (nc) samples. Two kinds of nc Cu samples were studied by using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM): an electro-deposited nc Cu sample with an average grain size of about 30 nm and one after cold-rolling in which the average grain size remain unchanged but the microstrain is substantially elevated. Measurement results indicated for the electro-deposited nc Cu, grain growth occurs at about 70 degrees C, which was prior to the major strain release process (onset at 150 degrees C). While for the as-rolled nc Cu, the grain growth onset temperature increases up to about 150 degrees C and that of the strain release process drops to about 115 degrees C. These results showed an evident correlation between the grain size stability and the microstrain in the nc materials. (C) 2000 Elsevier Science S.A. All rights reserved.
关键词:
nanocrystalline Cu;grain growth;strain release;microstrain;grain-growth;metals;alloys
