Dissertation > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials

Investigation of Stabilization and Application of Nanopowders Fabricated by Arc Discharge Method

Author SunWeiMin
Tutor LiuZheng
School Shenyang University of Technology
Course Materials Processing Engineering
Keywords Nano - powder Stabilizing treatment Oxidation resistance Conductive paste Corrosion-resistant magnetic fluid
CLC TB383.1
Type PhD thesis
Year 2008
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DC arc plasma prepared metal nano powder, nano powder of metal - ceramic composite industrialized technology and metal nano powder application for the purpose of stabilization of the nano-powder processing method, antioxidant properties and applications were studied. DC arc plasma prepared terpineol (C 10 H 18 O) composite nano powder coated Cu-Ag, the C coated Ni, Fe nano-powder, Mg nano-powder, Mg-Mg 2 Si-Si composite nano-powder and Fe-TiC composite nano powder. The use of X-ray diffraction (XRD), transmission electron microscopy (TEM), X photoelectron spectrum (XPS), Infrared Spectroscopy (IR), chemical analysis, the oxygen content analysis, differential thermal - thermal weight (DSC-TG) and vibrating sample magnetic meter (VSM) test technique to study the nano-powder phase composition, morphology, structure, anti-oxidant properties and magnetic. Cu-Ag composite nano powder coated with terpineol as the conductive phase was prepared by electro-conductive paste, and its preparation method and conductive properties; C coated with Ni, Fe nanopowder prepared as magnetic particles a corrosion-resistant, high- The viscosity of the magnetic fluid, its preparation method and corrosion resistance. For the metal nano-powder is used when preparing a conductive paste, the surface oxide layer is severely affected by the conductive properties, the development of a method for stabilizing a DC arc plasma producing metal nano powder, i.e. in the gas - liquid two-phase stabilization method. And terpineol was prepared using the method of the Cu-Ag-coated composite nano-powder, the obtained composite nano-powder having a double shell structure, the inner layer is a thin layer of the oxide layer, the outer molecular layer is terpineol. Cu-Ag composite nano powder than the single-layer structure oxide powder oxidation resistance and electrical conductivity with a double shell structure. atmosphere the pure CH 4 prepared for the DC arc plasma C-coated Ni, Fe nano powder containing a large amount of free carbon, severely reducing the problem of the saturation magnetization, the working atmosphere was changed to 50% CH . 4 the 20 H 2 30% Ar of a mixed atmosphere of the stabilization method. Prepared by C-coated Ni, Fe nano-powder free carbon content were reduced 11wt% and 12 wt%, saturation magnetization increased the 5.1A m 2 / kg and 45.5A · m 2 / kg. For the Mg nano powder has a very high surface activity, oxidation, flammable, explosive and difficult to mass production of research process DC arc plasma mass production of Mg nano-powder, powder stabilizing treatment and anti- oxidation. The results showed that in Ar, Ar H 2 and Ar CH a the Mg nano powder prepared under 4 three different working atmosphere, in an argon atmosphere containing a trace of oxygen and air stable treatment available stable Mg nanometer powder stability and oxidation resistance the Mg nano powder prepared under 4 atmosphere, which in Ar CH best. Legal system for mechanical alloying of Mg-based composite nanopowder time-consuming, energy consumption problem, a DC arc plasma pure Mg as raw materials, synthetic Mg-Mg in the atmosphere containing SiH 4 < sub> 2 Si-Si composite nano powder process, stabilizing treatment and oxidation resistance. The results showed that the stability of the Mg-Mg 2 Si-Si composite nano powder obtained after stabilizing treatment with argon containing of Trace oxygen and air. Under atmospheric conditions at room temperature, the powder the Mg 2 Si phase content is higher, the better the antioxidant. Powder temperature is higher than 410 ° C or so in the flowing air, accelerate the rate of oxidation of the powder. Dispersion strengthened iron-based alloy powder a long time, the problem of energy consumption for milling Preparation of TiC, DC arc plasma Fe-Ti alloy as raw materials, synthesized in the atmosphere containing CH 4 Fe-TiC composite nano powder process, stabilization processing method and oxidation resistance. The results show that the stability of Fe-TiC composite nano powder obtained after stabilizing treatment with argon containing of Trace oxygen and air. Powder Fe, TiC and a small amount of Fe 3 C, the morphology of the composite particles mainly sub-bell-shaped and polyhedral, the formation mechanism of the composite particles compliance find the VLS mechanism. And may occur in the vapor phase chemical reaction carried out thermodynamic calculations. Under atmospheric conditions at room temperature, the higher the content of TiC phase Powder antioxidant as possible. Temperature higher than 330 ° C in flowing air oxidation of the sample has accelerated markedly, TiC nano-particles oxidation and decomposition at about 410 ℃. For precious metals prices soared, making electronic pulp costs continue to increase this problem, the initial electronic paste Preparation of nanometer low-cost metal. The composite nano-Cu-Ag powder coated with terpineol as the conductive phase, terpineol solvent additives with ethyl cellulose as a carrier, the preparation of a conductive paste, the conductive paste in the sintering temperature of 180 ° C -200 ° C The resistivity was obtained, the holding time 60min-70min, the degree of vacuum was 1.33Pa conditions (1.10-2.16) × 10 -4 Ω · cm conductive film. Wu Nai corrosion, high viscosity of the magnetic fluid for the current domestic initial corrosion resistance, the high viscosity Ferrofluide research. C coated with Ni, Fe nanopowder as magnetic particles, oleic acid as a surfactant, the perfluoropolyether oil and a mixture of a small amount of silicone grease was prepared in the base fluid of the corrosion resistance, the high viscosity of the magnetic fluid. Preparation of magnetic fluid having better corrosion resistance. The magnetic liquid at 25 ° C viscosity 9Pa · S-25Pa · S, for 2pA S-16PA · S at 85 ° C viscosity, at room temperature under a saturation magnetization of the Ni magnetic liquid the 5.19A and m 2 / of the kg-17.83A · m 2 / kg Fe magnetic liquid 15.36A · m 2 / of KG-59.88A · m 2 / kg.

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