共查询到12条相似文献,搜索用时 68 毫秒
1.
Sincethethree terminal(3T)superconductor devicecombinedhightemperaturesuperconducting (HTS)filmwithcolossalmagnetoresistance(CMR) filmhashighergainandsensitivity,itisveryattrac tivetouse3Tsuperconductordeviceinelectronicap plications.Therehavebeenmanyef… 相似文献
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Sytchenko A. D. Sheveyko A. N. Levashov E. A. Kiryukhantsev-Korneev Ph. V. 《Russian Journal of Non-Ferrous Metals》2020,61(3):325-331
Russian Journal of Non-Ferrous Metals - Single- and double-layer coatings on 40Cr steel substrates have been obtained by electrospark alloying (ESA) and a combination of ESA technology and pulsed... 相似文献
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Al2O3-Y2O3 nano- and micro-composite coatings were deposited on Fe-9Cr-Mo substrates by using sol-gel composite coating technology. The processing includes dipping samples in a sol-gel solution dispersed with fine ceramic powders, which are prepared by high-energy ball milling. High-resolution microscopy (FE-SEM) analyses show that the coating is composed of composite particle clusters with an average diameter of 1μm, and the coating is relatively dense without cracking during drying and sintering stages. XRD analyses show that the oxide coating is mainly composed of α-Al2O3 and γ-Al2O3. The oxidation tests performed at 600℃ in air show that the coatings are provided with much improved resistance against high temperature oxidation and scale spallation. It is indicated that nano-structured composite particles and reactive elements are integrated into the coatings, which plays an important role in preventing agglomeration of nano-particles and initiation of cracks. 相似文献
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The influences of solidification rate on the microstructures of cast strips and corresponding sintered NdFeB magnets were investigated. The experimental results show that the volume fraction and size of columnar grains vary with the wheel speed V, and the fraction is highest to more than 90% with 3.5 μm in average width at V=2 m·s-1. The reasons for the improved magnetic performance were discussed based on the micromagnetic theory and microstructure analyses of the strips and sintered magnets. The magnetic properties of sintered NdFeB magnets made from the (Nd,Dy)13.0(Fe,Ga,Al)80.5B6.5 cast strip which was obtained at V=2 m·s-1 are as follows: Br=1.15 T(11.25 kG), iHc=2799 kA·m-1 (35.2 kOe) and (BH)max=242 kJ·m-3(30.35 MGOe). 相似文献
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Investigation of Coercivity Mechanism for Nd-Fe-B Magnets Prepared by Combination of Strip-Casting with Hydrogen Decrepitation Techniques 总被引:1,自引:1,他引:0
The coercivity mechanism of Nd-Fe-B magnets prepared by combination of strip-casting with hydrogen decrepi-tation techniques was investigated. The microstructure of (Nd0.935Dy0.065)14.5Fe79.4B6.1 magnet was observed. The average grain size is about 6 ~ 12 μm. The magnetizing field dependence of the hardmagnetic properties for the (Nd0.935Dy0.065)14.5 Fe79.4B6.1 and the temperature dependence of the coercivity for the Nd14.5Fe79.4B6.1 were investigated. Results show that the coereivity for magnets prepared by the combination of strip-casting with hydrogen decrepitation techniques is controlled by the nucleation mechanism. 相似文献
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In order to study the effect of alloy component on magnetic properties of NdFeB magnets, the experiment schemes are carried out by the uniform design theory, and the relationship between the component and the magnetic properties is established by artificial neural network(ANN) predicting model.The element contents of alloys are optimized by the ANN model.Meanwhile, the influences of mono-factor or multi-factor interaction on alloy magnetic properties are respectively discussed according to the curves ploted by ANN model.Simulation result shows that the predicted and measured results are in good agreement.The relative error is every low, the error is not more than 1.68% for remanence Br, 1.56% for maximal energy product (BH)m, and 7.73% for coercivity Hcj.Hcj can be obviously improved and Br can be reduced by increasing Nd or Zr content.Co and B have advantageous effects on increasing Br and disadvantageous effects on increasing Hcj.Influence of alloying elements on Hcj and Br are inverse, and the interaction among the alloying elements play an important role in the magnetic properties of NdFeB magnets.The ANN prediction model presents a new approach to investigate the nonlinear relationship between the component and the magnetic properties of NdFeB alloys. 相似文献
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Preparation and Corrosion Resistance of Rare Earth Conversion Coatings on AZ91 Magnesium Alloy 总被引:4,自引:2,他引:4
Lü Zushun 《中国稀土学报(英文版)》2005,23(5):555-558
Magnesiumalloysarewidelyusedinweaponin dustry,spacenavigationandhavegoodpotentialof applicationanddevelopmentindailycommunication facilitiesduetotheirpropertiesoflightweightandhighstrength[1].Appliedasstructuralmaterials,mag nesiumalloysmayeasilycrackduet… 相似文献
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Corrosion Resistance of Sintered NdFeB Permanent Magnet With Ni-P/TiO2 Composite Film 总被引:2,自引:0,他引:2
The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction (XRD), environmental scanning electron microscopy (ESEM), and energy dispersive X-ray spectrometer (EDX).The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet, in 0. 5 mol/L NaCl solution, was studied by potentiodynamic polarization, salt spray test and electrochemical impedance spectroscopy (EIS) techniques. The selfcorrosion current density (icorr) and the polarization resistance (Rp) of Ni-P/TiO2 film are 0. 22 μA/cm2 (about 14% of that of Ni-P coating), and 120 kΩ·cm2 (about 2 times of that of Ni-P coating), respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating, and the composite film increases the corrosion resistance of NdFeB magnet markedly. 相似文献
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The morphology and corrosion behavior of Ni/Al2O3 composite coatings prepared using double-pulsed electrodepositing technique after oxidized under 800℃ NaCl deposit in air environment were analyzed by scanning electrical microscope (SEM), X-ray diffraction (XRD) and energy dispersive spectrum (EDS). The results showed that the corrosion of all composite coatings was accelerated under NaCl deposits, and the corrosion products were rather porous with poor adherence to the matrix. Al2)O3 particles in the coatings can refine the grain size and improve the high temperature corrosion resistance of the coatings. Within the test scope, the more Al2O3 particles in the coatings, the lower corrosion rates could be obtained, and the corrosion mechanism was also discussed. 相似文献
11.
The technical parameters of HD process were studied, including the effects of temperature and neodymium contents on the incubation period of hydrogen absorption, hydrogen concentration and the rate of hydrogen absorbed. The results show that the incubation period is shortened and the rate of hydrogen absorbed is accelerated with rising temperature and surface area. These are attributed to the rising rate of hydrogen diffusion at higher temperature. The change of the incubation period and the rate of hydrogen absorbed have the similar trend resulted from the increasing content of the Nd-rich phase owing to the rising temperature. Moreover, the percent of the Nd-rich phase in the ingot can be calculated according to the total hydrogen weight gain. 相似文献
12.
The surface of carbon fiber reinforced Mg matrix (Cf/Mg) composites was modified by treatment of rare earth conversion coating, and nontoxic, non-pollution Ce conversion coatings were prepared. The effect of the coatings on corrosion behaviors of composites was investigated by electrochemical polarization technology and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. The higher Ecorr and lower icorr were obtained by Ce conversion coatings. EIS results showed that the higher values of R2 were obtained by treatment containing CeCl3, the high corrosion resistance occured in treatment containing CeCl3, the low corrosion resistance in uncoating sample, the coating of treatment containing Ce(NO3)3 was medium. The microstructure of Ce conversion coatings was observed by scanning electron microscopy (SEM), and the elements of corresponding for coatings was characterized by energy dispersive spectrometer (EDS). The micro-cracks and Ce-riched spherical particles were characteristics of these coatings. 相似文献