A simple and fast method of preparation of vanadium carbide(V_8 C_7) nanopowders using mechanical alloying assisted microwave heating method was demonstrated. The micron-sized V_2O_5 and nano-sized carbon black were u...A simple and fast method of preparation of vanadium carbide(V_8 C_7) nanopowders using mechanical alloying assisted microwave heating method was demonstrated. The micron-sized V_2O_5 and nano-sized carbon black were used as starting materials. The as-prepared powders were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), thermogravimetric and differential scanning calorimetry(TG-DSC), transmission electron microscopy(TEM), and X-ray photoelectron spectroscopy(XPS) techniques. The experimental results show that the V_8C_7 powders can be obtained by microwave heating at 1 100 ℃ for 1 h(34 wt% C). The synthesized powders show good dispersion and are mainly composed of spherical or near-spherical particles with a mean diameter of about 30 nm. The XPS spectra show that the surface of the specimen mainly consists of V, C, and O three species elements.展开更多
High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlat...High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlation was developed for certain temperatures to find an equation for the relation between time and weight. The thermal treatment was done for different quantities at certain times. The proposed equation studies the correlation between temperature, time, and weight. For each temperature, a number of points were recorded from the measured oxidation curve. The shape of the curves is well-represented in this paper. The final results will present the highest temperature, the maximum weight, and the maximum time for full oxidation at high and low temperatures.展开更多
The 11.3 nm diameter nanopowders of Ni dominated Ni（Fe） solid solution can be prepared by（using） aluminum powder to react with FeSO4\5（NH4）2SO4 and NiSO4\5（NH4）SO4 mixed solution.In the product,the Fe atoms re...The 11.3 nm diameter nanopowders of Ni dominated Ni（Fe） solid solution can be prepared by（using） aluminum powder to react with FeSO4\5（NH4）2SO4 and NiSO4\5（NH4）SO4 mixed solution.In the product,the Fe atoms replaced parts of the Ni atoms.While the mass fraction of Ni2+/（Fe2++Ni2+） in the solution is higher than 76%,solid solution of homogenous phase Ni（Fe） can be obtained.If the content of Ni2+/（Fe2++Ni2+） lower than this point,the Ni（Fe）+Fe or Fe+Ni0.36Fe0.64 mixed phase nanopowders will be produced.展开更多
基金Funded by the Natural Science Foundation of China(21404032)the Program for Science&Technology Innovation Talents in Universities of Henan Province(16HASTIT011)+3 种基金the Funding Scheme for Young Teachers of Higher School in Henan Province(2014GGJS-062)the Fundamental Research Funds for the Henan Provincial Colleges and Universities(2014YWQQ19)the Development of Science and Technology Plan Projects of Zhengzhou City(20140771)the Foundation of Henan University of Technology(2014JCYJ13),China
文摘A simple and fast method of preparation of vanadium carbide(V_8 C_7) nanopowders using mechanical alloying assisted microwave heating method was demonstrated. The micron-sized V_2O_5 and nano-sized carbon black were used as starting materials. The as-prepared powders were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), thermogravimetric and differential scanning calorimetry(TG-DSC), transmission electron microscopy(TEM), and X-ray photoelectron spectroscopy(XPS) techniques. The experimental results show that the V_8C_7 powders can be obtained by microwave heating at 1 100 ℃ for 1 h(34 wt% C). The synthesized powders show good dispersion and are mainly composed of spherical or near-spherical particles with a mean diameter of about 30 nm. The XPS spectra show that the surface of the specimen mainly consists of V, C, and O three species elements.
文摘High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlation was developed for certain temperatures to find an equation for the relation between time and weight. The thermal treatment was done for different quantities at certain times. The proposed equation studies the correlation between temperature, time, and weight. For each temperature, a number of points were recorded from the measured oxidation curve. The shape of the curves is well-represented in this paper. The final results will present the highest temperature, the maximum weight, and the maximum time for full oxidation at high and low temperatures.
文摘The 11.3 nm diameter nanopowders of Ni dominated Ni（Fe） solid solution can be prepared by（using） aluminum powder to react with FeSO4\5（NH4）2SO4 and NiSO4\5（NH4）SO4 mixed solution.In the product,the Fe atoms replaced parts of the Ni atoms.While the mass fraction of Ni2+/（Fe2++Ni2+） in the solution is higher than 76%,solid solution of homogenous phase Ni（Fe） can be obtained.If the content of Ni2+/（Fe2++Ni2+） lower than this point,the Ni（Fe）+Fe or Fe+Ni0.36Fe0.64 mixed phase nanopowders will be produced.
