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Mohammad Ghambari - One of the best experts on this subject based on the ideXlab platform.

  • Sintering of grey cast Iron Powder recycled via jet milling
    Materials & Design, 2013
    Co-Authors: Mahdokht Shaibani, Nicolas Eshraghi, Mohammad Ghambari
    Abstract:

    Abstract Porous grey cast Iron Powder metallurgy parts were made from grey cast Iron Powder manufactured via target jet milling of machining scraps. The Powders were used in the as-milled state without any further physical or heat treatment. Sintering was conducted at 1025, 1100 and 1175 °C in an argon atmosphere and the effect of sintering temperature on microstructure, sintered density and apparent hardness of the grey cast Iron specimens pressed to 5.8 g/cm 3 was investigated. Although diffusion processes were partially activated at 1025 °C, it was determined that a temperature of 1175 °C proved to be the ideal temperature for solid state sintering of grey cast Iron parts. The hardness value and sintered density for the specimens sintered at 1175 °C were found to be 96 BHN and 6.1 g/cm 3 (around 15% porosity) respectively, all of which lends itself to promising properties for making self-lubricating bearings and parts with sliding properties.

M. Ghambari - One of the best experts on this subject based on the ideXlab platform.

Yicheng Ge - One of the best experts on this subject based on the ideXlab platform.

  • fabrication of carbonyl Iron Powder sio2 reduced Iron Powder sio2 soft magnetic composites with a high resistivity and low core loss
    Journal of Magnetism and Magnetic Materials, 2018
    Co-Authors: Liya Li, Aikun Li, Jianhong Yi, Yicheng Ge
    Abstract:

    Abstract Carbonyl Iron Powder (CIP) and reduced Iron Powder (RIP) were homogeneously coated with an SiO2 insulating layer by a controlled in-suit chemical deposition procedure and used as raw materials to fabricate CIP/SiO2-RIP/SiO2 (C-R) soft magnetic composites (SMCs) by Powder metallurgy techniques. Compared with RIP/SiO2 Powders, CIP/SiO2 Powders possess a higher SiO2 content and more stable Si-O covalent network. The addition of CIP/SiO2 to the C-R SMCs leads to a significantly increase in the resistivity due to the full electrical isolation of the RIP/SiO2 particles. Transmission electron microscopy analysis confirms that a SiO2 amorphous layer approximately 100–400 nm in thickness grows with a high packing density and adheres tightly to the Iron grains, resulting in the effective constraint of electron transfer between the Si and O atoms. Annealed C-R SMCs containing 15–20 wt% CIP/SiO2 have optimum properties with a high resistivity of 4980–6383 μΩ·m and a low core loss of 19.08–23.66 W/kg (50 mT, 100 kHz). The results of this present study provide a significant method to improve resistivity and reduce core loss.

Mahdokht Shaibani - One of the best experts on this subject based on the ideXlab platform.

  • Sintering of grey cast Iron Powder recycled via jet milling
    Materials & Design, 2013
    Co-Authors: Mahdokht Shaibani, Nicolas Eshraghi, Mohammad Ghambari
    Abstract:

    Abstract Porous grey cast Iron Powder metallurgy parts were made from grey cast Iron Powder manufactured via target jet milling of machining scraps. The Powders were used in the as-milled state without any further physical or heat treatment. Sintering was conducted at 1025, 1100 and 1175 °C in an argon atmosphere and the effect of sintering temperature on microstructure, sintered density and apparent hardness of the grey cast Iron specimens pressed to 5.8 g/cm 3 was investigated. Although diffusion processes were partially activated at 1025 °C, it was determined that a temperature of 1175 °C proved to be the ideal temperature for solid state sintering of grey cast Iron parts. The hardness value and sintered density for the specimens sintered at 1175 °C were found to be 96 BHN and 6.1 g/cm 3 (around 15% porosity) respectively, all of which lends itself to promising properties for making self-lubricating bearings and parts with sliding properties.

A I Hengyu - One of the best experts on this subject based on the ideXlab platform.

  • kinetics and corrosion products of aqueous nitrate reduction by Iron Powder without reaction conditions control
    Journal of Environmental Sciences-china, 2009
    Co-Authors: Xiaohong Guan, A I Hengyu
    Abstract:

    Although considerable research has been conducted on nitrate reduction by zero-valent Iron Powder (Fe0), these studies were mostly operated under anaerobic conditions with invariable pH that was unsuitable for practical application. Without reaction conditions (dissolved oxygen or reaction pH) control, this work aimed at subjecting the kinetics of denitrification by microscale Fe0 (160–200 mesh) to analysis the factors affecting the denitrification of nitrate and the composition of Iron reductive products coating upon the Iron surface. Results of the kinetics study have indicated that a higher initial concentration of nitrate would yield a greater reaction rate constant. The reduction rate of nitrate increased with increasing Fe0 dosage. The reaction can be described as a pseudo-first order reaction with respect to nitrate concentration or Fe0 dosage. Experimental results also suggested that nitrate reduction by microscale Fe0 without reaction condition control primarily was an acid-driven surface-mediated process, and the reaction order was 0.65 with respect to hydrogen ion concentration. The analyses of X-ray diffractometry and X-ray photoelectron spectroscopy indicated that a black coating, consisted of Fe2O3, Fe3O4 and FeO(OH), was formed on the surface of Iron grains as an Iron corrosion product when the system initial pH was lower than 5. The proportion of FeO(OH) increased as reaction time went on, whereas the proportion of Fe3O4 decreased.

  • kinetics and corrosion products of aqueous nitrate reduction by Iron Powder without reaction conditions control
    Journal of Environmental Sciences-china, 2009
    Co-Authors: Xiaomeng Fan, Xiaohong Guan, M A Jun, A I Hengyu
    Abstract:

    Although considerable research has been conducted on nitrate reduction by zero-valent Iron Powder (Fe0), these studies were mostly operated under anaerobic conditions with invariable pH that was unsuitable for practical application. Without reaction conditions (dissolved oxygen or reaction pH) control, this work aimed at subjecting the kinetics of denitrification by microscale Fe0 (160–200 mesh) to analysis the factors affecting the denitrification of nitrate and the composition of Iron reductive products coating upon the Iron surface. Results of the kinetics study have indicated that a higher initial concentration of nitrate would yield a greater reaction rate constant. The reduction rate of nitrate increased with increasing Fe0 dosage. The reaction can be described as a pseudo-first order reaction with respect to nitrate concentration or Fe0 dosage. Experimental results also suggested that nitrate reduction by microscale Fe0 without reaction condition control primarily was an acid-driven surface-mediated process, and the reaction order was 0.65 with respect to hydrogen ion concentration. The analyses of X-ray diffractometry and X-ray photoelectron spectroscopy indicated that a black coating, consisted of Fe2O3, Fe3O4 and FeO(OH), was formed on the surface of Iron grains as an Iron corrosion product when the system initial pH was lower than 5. The proportion of FeO(OH) increased as reaction time went on, whereas the proportion of Fe3O4 decreased.