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Vanadium Carbide Coating Growth on Die Steel Substrate in Borax Salt Bath 被引量:2
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作者 王洪福 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第4期600-603,共4页
Vanadium pentoxide, borax, boron carbide and sodium fluoride were used to grow vanadium carbide coating on die steel(Cr12, Cr12MoV) surface at 950 ℃ by TD process, which extended the life period of Cr12 and Cr12MoV... Vanadium pentoxide, borax, boron carbide and sodium fluoride were used to grow vanadium carbide coating on die steel(Cr12, Cr12MoV) surface at 950 ℃ by TD process, which extended the life period of Cr12 and Cr12MoV as punching die. Kinetics of vanadium carbide coating growth was brought forward and verified by comparison of the mathematical model with the experimental results. The thickness of coating was illustrated by SEM. The chemical constituent of coating and remnants were tested by XRD. To increase the thickness, rare earths (FeSiRe23) were added to the borax salt bath. The electronic probe microanalysis (EPMA) revealed that the addition of rare earths could decrease carbon concentration in the coating and increase the depth of vanadium carbide coating. 展开更多
关键词 vanadium carbide coating TD process punching die rare earths
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Effect of vanadium carbide on commercial pure aluminum 被引量:2
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作者 Hua-ping Sun Jun Wu +2 位作者 Tian Tang Bo Fan Zheng-hua Tang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第7期833-841,共9页
The effect of vanadium carbide(VC) on the grain size of commercial pure aluminum was experimentally investigated by varying the content of VC, the holding time, and casting temperature. The refining efficiencies of ... The effect of vanadium carbide(VC) on the grain size of commercial pure aluminum was experimentally investigated by varying the content of VC, the holding time, and casting temperature. The refining efficiencies of VC and Al5Ti1 B were also compared. The refined samples of commercial pure aluminum were examined using optical microscopy, scanning electron microscopy(SEM) and energy-dispersive spectroscopy(EDS). The results suggest that VC is a good refiner of commercial pure aluminum. The addition of only 0.3wt% VC can decrease the grain size of aluminum to 102 μm, whereas the casting temperature and holding time have little effect on the grain size. The refining efficiency of VC is better than that of Al5Ti1 B. The VC particles in molten aluminum act as nuclei and the grain refinement of aluminum alloys by VC particles is achieved via heterogeneous nucleation. 展开更多
关键词 grain refinement vanadium carbide heterogeneous nucleation aluminum
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Effect of vanadium and chromium on the microstructural features of V–Cr–Mn–Ni spheroidal carbide cast irons 被引量:3
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作者 V.G.Efremenko K.Shimizu +3 位作者 A.P.Cheiliakh T.V.Kozarevskaya K.Kusumoto K.Yamamoto 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2014年第11期1096-1108,共13页
The objective of this investigation is to study the influence of vanadium(5.0wt%–10.0wt%) and chromium(0–9.0wt%) on the microstructure and hardness of Cr-V-Mn-Ni white cast irons with spheroidal vanadium carbide... The objective of this investigation is to study the influence of vanadium(5.0wt%–10.0wt%) and chromium(0–9.0wt%) on the microstructure and hardness of Cr-V-Mn-Ni white cast irons with spheroidal vanadium carbides. The alloys' microstructural features are presented and discussed with regard to the distribution of phase elements. The structural constituents of the alloys are spheroidal VC, proeutectoid cementite, ledeburite eutectic, rosette-shaped carbide eutectic(based on M7C3), pearlite, martensite, and austenite. Their combinations and area fraction(AF) ratios are reported to be influenced by the alloys' chemical composition. Spheroidized VC particles are found to be sites for the nucleation of carbide eutectics. Cr and V are shown to substitute each other in the VC and M7C3 carbides, respectively. Chromium alloying leads to the formation of a eutectic(γ-Fe + М7С3), preventing the appearance of proeutectoid cementite in the structure. Vanadium and chromium are revealed to increase the total carbide fraction and the amount of austenite in the matrix. Cr is observed to play a key role in controlling the metallic matrix microstructure. 展开更多
关键词 cast irons carbides microstructure vanadium chromium austenite pearlite
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Vanadium-modified hard carbon spheres with sufficient pseudographitic domains as high-performance anode for sodium-ion batteries 被引量:4
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作者 Fuping Chen Yujie Di +6 位作者 Qiong Su Dongming Xu Yangpu Zhang Shuang Zhou Shuquan Liang Xinxin Cao Anqiang Pan 《Carbon Energy》 SCIE CSCD 2023年第2期12-23,共12页
Hard carbons are promising anode materials for sodium-ion batteries.To meet practical requirements,searching for durable and conductive carbon with a stable interface is of great importance.Here,we prepare a series of... Hard carbons are promising anode materials for sodium-ion batteries.To meet practical requirements,searching for durable and conductive carbon with a stable interface is of great importance.Here,we prepare a series of vanadiummodified hard carbon submicrospheres by using hydrothermal carbonization followed by high-temperature pyrolysis.Significantly,the introduction of vanadium can facilitate the nucleation and uniform growth of carbon spheres and generate abundant V-O-C interface bonds,thus optimizing the reaction kinetic.Meanwhile,the optimized hard carbon spheres modified by vanadium carbide,with sufficient pseudographitic domains,provide more active sites for Na ion migration and storage.As a result,the HC/VC-1300 electrode exhibits excellent Na storage performance,including a high capacity of 420 mAh g^(-1) at 50mA g^(-1) and good rate capability at 1 A g^(-1).This study proposes a new strategy for the synthesis of hard carbon spheres with high tap density and emphasizes the key role of pseudographitic structure for Na storage and interface stabilization. 展开更多
关键词 anode materials hard carbon sodium-ion batteries stable interface vanadium carbide
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Electrochemical Behavior of Vanadium Carbide in Neutral Aqueous Electrolytes
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作者 Chaofan Chen Di Pang +3 位作者 Xiaotong Wang Gang Chen Fei Du Yu Gao 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第5期143-147,共5页
The V_2C compound,belonging to the group of two-dimensional transition metal carbonitrides,or MXenes,has demonstrated a promising electrochemical performance in capacitor applications in acidic electrolytes;however,th... The V_2C compound,belonging to the group of two-dimensional transition metal carbonitrides,or MXenes,has demonstrated a promising electrochemical performance in capacitor applications in acidic electrolytes;however,there is evidence to suggest that V_2C is unstable in an acidic environment.On the other hand,the performance of V_2C in neutral aqueous electrolytes is still moderate,and has not yet been systematically studied.The charge storage mechanism in a V_2C electrode,employed in neutral aqueous electrolytes,is investigated via cyclic voltammetry testing and in situ x-ray diffraction(XRD).Good specific capacitances are achieved,specifically208 F/g in 0.5 M Li_2SO_4,225 F/g in 1 M MgSO_4,120 F/g in 1 M Na_2 SO_4,and 104 F/g in 0.5 M K_2SO_4.Using in situ XRD,we observe that,during the charge and discharge process,the c-lattice parameter shrinks or expands by up to 0.25 A in MgSO_4,and 0.29 A in Li_2SO_4 which demonstrates the intercalation/de-intercalation of cations into the d-V_2C layer. 展开更多
关键词 Electrochemical Behavior of vanadium carbide in Neutral Aqueous Electrolytes
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Effects of Mo Contents in Matrix on Microstructure and Properties of Vanadium Carbide Coating Formed by Thermal Diffusion Treatment 被引量:2
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作者 Zhi-tao HUANG Wen-huai TIAN 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2014年第1期104-108,共5页
Thermal diffusion salt-bath vanadizing was finished for Crl2MoV die steel, in order to investigate the properties of vanadium carbide coatings related with the Mo contents in Crl2MoV die steel. Scanning electron micro... Thermal diffusion salt-bath vanadizing was finished for Crl2MoV die steel, in order to investigate the properties of vanadium carbide coatings related with the Mo contents in Crl2MoV die steel. Scanning electron micro- scopic observation reveals that Mo can decrease the growth rate of coating as a carbide forming element. Besides, Mo element can promote grain refinement of the coating. X-ray diffraction analysis shows that the different Mo contents have no influence on the phase structure of the coatings. Energy dispersive spectrum analysis and mechanical properties test show that Mo can diffuse into the coating and make a strengthening effect on the coating. 展开更多
关键词 vanadium carbide salt-bath carbide forming element grain refinement mechanical property
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Photoelectron Spectroscopy and Density Functional Theory Calculations of Binary VnC30/-(n=1-6) Clusters
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作者 Jinyun Yuan Peng Wang +5 位作者 Xiling Xu Yonghui Zhang Linghao He Hong-Guang Xu Gao-Lei Hou Wei-Jun Zheng 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第6期907-915,I0039-I0054,I0073,共26页
Transition metal carbides have been shown to exhibit good catalytic performance that depends on their compositions and morphologies,and understanding such catalytic properties requires knowledge of their precise geome... Transition metal carbides have been shown to exhibit good catalytic performance that depends on their compositions and morphologies,and understanding such catalytic properties requires knowledge of their precise geometry,determination of which is challenging,particularly for clusters formed by multiple elements.In this study,we investigate the geometries and electronic structures of binary V_(n)C_(3)-(n=1-6)clusters and their neutrals using photoelectron spectroscopy and theoretical calculations based on density functional theory.The adiabatic detachment energies of V_(n)C_(3)-,or equally,the electron affinities of V_(n)C_(3),have been determined from the measured photoelectron spectra.Theoretical calculations reveal that the carbon atoms become separate when the number of V atoms increases in the clusters,i.e.,the C-C interactions present in small clusters are replaced by V-C and/or V-V interactions in larger ones.We further explore the composition dependent formation of cubic or cube-like structures in 8-atom VnCm(n+m=8)clusters. 展开更多
关键词 vanadium carbide cluster Photoelectron spectroscopy Density functional theory Cubic or cube-like structure
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Preparation and wear properties of high-vanadium alloy composite layer 被引量:1
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作者 Fangfang WANG Liujie XU +3 位作者 Shizhong WEI Xi WANG Chong CHEN Yucheng ZHOU 《Friction》 SCIE EI CAS CSCD 2022年第8期1166-1179,共14页
A high-vanadium alloy composite layer was prepared on the surface of a carbon steel using cast composite technology,and the wear properties of the composite layer were investigated.The results showed that the microstr... A high-vanadium alloy composite layer was prepared on the surface of a carbon steel using cast composite technology,and the wear properties of the composite layer were investigated.The results showed that the microstructure of the composite layer was composed of primary vanadium carbides(VC),flake martensite,residual austenite,and fine VC.The hardness of the cast alloy layer was 63 HRC.The abrasive wear resistance and impact wear resistance were increased by 60%and 26%,respectively,compared with those of high-chromium cast iron.The excellent wear resistance of the cast alloy layer is attributed to the high-hardness primary vanadium carbide and the large number of fine secondary vanadium carbides precipitated out of the cast alloy layer. 展开更多
关键词 high-vanadium alloy layer wear resistance vanadium carbide solidification process
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