Beijing Key Laboratory of Precision Alloys

Beijing, China

Beijing Key Laboratory of Precision Alloys

Beijing, China
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Lu F.,Control Iron and Steel Research Institute, China | Lu F.,University of Science and Technology Beijing | Lu F.,Beijing Key Laboratory of Precision Alloys | Wu B.,Control Iron and Steel Research Institute, China | And 6 more authors.
Gongneng Cailiao/Journal of Functional Materials | Year: 2016

After proper heat treatment, MnCu alloys could exhibit excellent damping and mechanical properties. In this paper, Mn20Cu5Ni2FeCe alloy was prepared by vacuum melting, and the effect of aging temperature on the microstructure and damping property of the alloy were investigated by XRD, TEM and DMA techniques. It is shown that the as-quenched Mn20Cu5Ni2FeCe alloy has a single fcc phase structure, with tanδ of less than 0.01. During aging process spinodal decomposition occurs and Mn-rich phase precipitates from the matrix phase. The damping capacity was significantly improved and the value of tanδ reaches 0.045 when aging at 400℃. The results indicated that the damping capacity of the alloy increases with the decrease of the testing environment temperature, implying that the Mn20Cu5Ni2FeCe damping alloy could possess good application prospects at low temperature. © 2016, Chongqing Functional Materials Periodical Press Co. Ltd. All right reserved.


Wang Z.,Central South University | Lu F.,Control Iron and Steel Research Institute, China | Lu F.,Beijing Key Laboratory of Precision Alloys | Wu B.,Control Iron and Steel Research Institute, China | And 7 more authors.
Gongneng Cailiao/Journal of Functional Materials | Year: 2016

M2052 damping alloy was prepared through reaction sintered method using high-purity simple substance powders of Mn, Cu, Ni, Fe. Not only the effect of different sintering temperature on the density, porosity and mechanical properties of the sintering alloy was studied, but also the phase composition of the sintered sample was analyzed. It is demonstrated that the M2052 alloy sintered at 1 223 K was essentially γ-MnCu solid solution. The density of M2052 alloy sintered at 1 223 K was 6.23 g/cm-3, the relative density was 87.2% and the bending strength reach to 487 MPa. The results show that the damping capacity maintained at a very high level (tanδ ranges from 0.11-0.12) and the damping ability changes little as frequency increases from 0-100 Hz. © 2016, Chongqing Functional Materials Periodical Press Co. Ltd. All right reserved.


He J.,Control Iron and Steel Research Institute, China | He J.,Beijing Key Laboratory of Precision Alloys | An J.,Control Iron and Steel Research Institute, China | An J.,Beijing Key Laboratory of Precision Alloys | And 8 more authors.
Journal of Applied Physics | Year: 2015

Field-induced unidirectional anisotropy of Co-based amorphous ribbons was discussed by magnetization measurement. The shifted hysteresis loops of Co58Fe5Ni10Si11B16 amorphous ribbons were obtained by annealing the samples in longitudinal magnetic field. Here, the feasibility of employing the longitudinal pulse field to tailor the anisotropy characteristic is demonstrated. It is found that the shifted loops can be technically controlled by enhancing the pulse field to modulate the magnetic anisotropy from unidirectional to uniaxial, and even back to unidirectional. The surface domains scan gives strong evidence that the pulse field can be one of the skillful methods to navigate the unidirectional anisotropy in the amorphous ribbons for potential applications. © 2015 AIP Publishing LLC.


Yuan Z.M.,Control Iron and Steel Research Institute, China | Yuan Z.M.,Beijing Key Laboratory of Precision Alloys | He J.,Control Iron and Steel Research Institute, China | He J.,Beijing Key Laboratory of Precision Alloys | And 8 more authors.
Journal of Applied Physics | Year: 2015

NaZn13-type La(Fe0.94Co0.06)11.8Si1.2 alloys were manufactured to investigate the influence of their microstructural change on magnetic refrigeration performance during magnetic field cycling. The magnetic refrigeration performance measurements indicate that both the large magnetic entropy change value (ΔS = 14.1 J kg-1 K-1) and maximum adiabatic temperature change (ΔT = 2.2 K) are favorable for the alloys to be superior candidate of magnetic refrigerants. However, the alloys exhibit nearly 10% decrease of ΔS and ΔT when they performed cycling ten-thousand times. More than thousand times of cycles induce local stress and grain cleavages presented by the accumulation of irreversible microstructure changes such as micro-cracks and sub-boundaries. According to the domain observation for the alloys with different field cycles, these microstructure characteristics accompany with the reconfiguration of the local magnetic domains and increase of domain wall energy, which are considered to be the reason of the decrease of ΔS. © 2015 AIP Publishing LLC.


Yuan Z.,Control Iron and Steel Research Institute, China | Yuan Z.,Inner Mongolia University of Science and Technology | Yuan Z.,Beijing Key Laboratory of Precision Alloys | Yang T.,Control Iron and Steel Research Institute, China | And 9 more authors.
International Journal of Hydrogen Energy | Year: 2016

The composition, phase components, and microstructure of Mg-based Sm5Mg41 alloy prepared by vacuum induction melting technique were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscopy (HRTEM). The gaseous hydrogen ab/desorption properties of the alloy were measured by an automatically controlled Sieverts apparatus. The results indicate that the as-cast alloy consists of two phases, major phase Sm5Mg41 and secondary phase SmMg3. The MgH2 and Sm3H7 phases form after hydrogen absorption, while Mg and Sm3H7 phases exist after hydrogen desorption at 340 °C. Field Emission Transmission Electron Microscopy (FETEM) observation reveals the microstructure and phase distribution of Mg-based Sm5Mg41 alloy before and after hydrogen absorption and the hydriding and dehydriding reaction pathways as follow: Sm5Mg41 + SmMg3 + H2 → Sm3H7 + MgH2 ↔ Sm3H7 + Mg + H2. The hydrogen storage thermodynamics and kinetics of the Mg-based Sm5Mg41 alloy are improved as a result of the formation of the Sm3H7 nanoparticles. Consequently, the starting dehydrogenation temperature of the alloy hydride is about 270 °C. The dehydrogenation and hydrogenation activation energies of the alloy are estimated to be 135.28 and 77.802 kJ/mol, which suggests that the Sm3H7 nanoparticles play a beneficial role to reduce the total potential barrier that the hydrogen absorption or desorption reaction must overcome. The hydrogenation enthalpy of the alloy was determined to be -76.52 kJ/mol H2, indicating that adding Sm can slightly alter the hydrogen absorption thermodynamic property of Mg-based alloy. The desorption property improved by alloying Sm is attribute to the enhanced kinetics rather than the variation in the thermodynamics. © 2016 Hydrogen Energy Publications, LLC.


Yang T.,Control Iron and Steel Research Institute, China | Yang T.,Inner Mongolia University of Science and Technology | Yang T.,Beijing Key Laboratory of Precision Alloys | Yuan Z.,Control Iron and Steel Research Institute, China | And 9 more authors.
International Journal of Hydrogen Energy | Year: 2016

Mg88Y12 binary alloy was fabricated by vacuum induction melting technique. The phase compositions and microstructures of the alloy were analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Then the alloy powders were subjected to isothermal hydrogen absorption/desorption characterizations, differential scanning calorimetry (DSC) analysis and pressure-composition isotherms (PCI) measurements. XRD and SEM results showed that the alloy was composed of primary Mg24Y5 intermetallic and fine dendritic eutectic Mg-Mg24Y5 mixture. First hydrogenation process resulted in an irreversible two-step disproportion reaction: Mg24Y5 + H2 → Mg + YH2 → MgH2 + YH2 + YH3, and 6.479 wt.% hydrogen was absorbed at 380 °C. For further absorption/desorption cycles, the alloy had a reversible hydrogen capacity of about 5.6 wt.% due to the fact that the YH2 has a very high thermal stability and can not desorb hydrogen at the present experimental temperature. The hydrogen absorption and desorption rates were gradually improved by increasing hydriding/dehydriding cycle times because the alloy particles significantly cracked and pulverized during the first few cycles. The activated alloy exhibited well isothermal hydrogen absorption kinetics, but the dehydrogenation occurred at relatively high temperature. DSC measurements indicated that the desorption process of the fully hydrogenated alloy began at about 320 °C and peaked at 367 °C when the heating rate was 3 °C/min. The activation energy was determined as 122 and 116 kJ/mol according to the isothermal dehydrogenation kinetics at different temperatures and DSC curves at different heating rates. Moreover, the enthalpy and entropy changes for hydrogen absorption/desorption were calculated to be -79.8 kJ/mol H2, -139 J/K/mol H2 and 81.2 kJ/mol H2, 141 J/K/mol H2, respectively. Copyright © 2015 Hydrogen Energy Publications, LLC.


Yang T.,Control Iron and Steel Research Institute, China | Yang T.,Inner Mongolia University of Science and Technology | Yang T.,Beijing Key Laboratory of Precision Alloys | Yuan Z.,Control Iron and Steel Research Institute, China | And 10 more authors.
Materials and Design | Year: 2016

Intermetallic compounds with the nominal formula LaMgNi3.6M0.4 (M = Ni, Co, Mn, Cu, Al) were prepared through induction melting, and the structure and hydrogen storage properties of the resultant alloys were extensively investigated. Results showed that the alloys exhibit sizable hydrogen absorption capacity and that elemental substitution significantly influences their microstructure and hydrogen storage properties. The discharge capacities of the alloy electrodes decrease in the order Co > Ni > Al > Cu > Mn. Moreover, the electrochemical kinetics of the alloys depend on their microstructures and phase compositions. Smaller grain size is helpful to improve the electrochemical kinetics. The gaseous hydrogen absorption capacities of the alloys are approximately 1.7 wt.% in the first hydrogenation process. Cracking caused by hydrogenation and dehydrogenation also significantly improves the hydrogen absorption kinetics of the alloy particles. The hydrogen storage capacities of the alloys rapidly decrease with increasing cycle number. This result is attributed to amorphisation of the LaMgNi4 phase during hydrogen absorption-desorption cycling (H2-induced amorphisation). Our findings provide new insights into the capacity degradation mechanism of La-Mg-Ni system hydrogen storage alloys that may improve their cycling stability. © 2015 Elsevier Ltd.


Huang S.-L.,Control Iron and Steel Research Institute, China | Huang S.-L.,University of Science and Technology Beijing | Huang S.-L.,Beijing Key Laboratory of Precision Alloys | Feng H.-B.,Control Iron and Steel Research Institute, China | And 12 more authors.
International Journal of Minerals, Metallurgy and Materials | Year: 2015

A systemic investigation was done on the chemistry and crystal structure of boundary phases in sintered Ce9Nd21FebalB1 (wt%) magnets. Ce2Fe14B is believed to be more soluble in the rare-earth (RE)-rich liquid phase during the sintering process. Thus, the grain size and oxygen content were controlled via low-temperature sintering, resulting in high coercivity and maximum energy products. In addition, Ce formed massive agglomerations at the triple-point junctions, as confirmed by elemental mapping results. Transmission electron microscopy (TEM) images indicated the presence of (Ce,Nd)Ox phases at grain boundaries. By controlling the composition and optimizing the preparation process, we successfully obtained Ce9Nd21FebalB1 sintered magnets; the prepared magnets exhibited a residual induction, coercivity, and energy product of 1.353 T, 759 kA/m, and 342 kJ/m3, respectively. © 2015, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.


Wang M.,Control Iron and Steel Research Institute, China | Wang M.,Beijing Key Laboratory of Precision Alloys | Du Z.,Control Iron and Steel Research Institute, China | Du Z.,Beijing Key Laboratory of Precision Alloys | And 4 more authors.
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2016

The TiO2 nanoparticles are wildly used in dye sensitized solar cell (DSSC) serving as the photoanode. A new type of DSSC was designed with TiO2 nanoparticles coated Ag nanowire heterojunction as the photoanode. Photoanodes with different TiO2 crystalline degrees were prepared at different hydro-thermal reaction temperatures. The morphology and microstructure were studied by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and the effect of TiO2 crystalline degree on the performance of the cells was characterized by current-voltage (I-V) test and ultraviolet photoelectron spectroscopy (UPS). The result showed that the performance of cells was clearly influenced by TiO2 crystalline degree. The cell with lower TiO2 crystalline degree displayed higher open circuit voltage (Voc). The one with higher TiO2 crystalline degree showed larger short circuit current density (Jsc). Different Voc arised from the change in electronic structure of TiO2 coating layer. While different Jsc was caused by the change in surface area of the photoanodes and electron injecting efficiency from excited states of sensitizers to TiO2 conducting bands. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.


Lu F.-S.,Control Iron and Steel Research Institute, China | Lu F.-S.,University of Science and Technology Beijing | Lu F.-S.,Beijing Key Laboratory of Precision Alloys | Wu B.,Control Iron and Steel Research Institute, China | And 6 more authors.
Rare Metals | Year: 2016

Mn-Cu alloys could exhibit high damping ability and excellent mechanical properties after proper heat treatment. In order to reduce the influence of impurity elements on damping capacity of Mn-Cu alloys, rare element cerium (Ce) was added into MnCuNiFe alloys. It is indicated that the contents of C, S and Si which have adverse effects on the damping capacity decrease and the grains are refined with the Ce content increasing. The microstructure of the MnCuNiFeCe alloy was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The damping ability (tanδ) of the alloy was characterized by dynamical mechanical analyzer (DMA). It is found that the damping ability (tanδ) retains a very high level which is all above 0.05 from the temperature of −50 to 75 °C with the addition of Ce element. It is expected that the Ce alloying MnCuNiFe alloy with refined grains could find wide applications in the field of industry. © 2016 The Nonferrous Metals Society of China and Springer-Verlag Berlin Heidelberg

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