The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

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

  • Solid state and liquid Phase Sintering of mechanically activated w 20 wt cu powder mixture
    Journal of Alloys and Compounds, 2008
    Co-Authors: Mohammad H Maneshian, A Simchi
    Abstract:

    Abstract W–20 wt.% Cu powder mixture was mechanically alloyed by high-energy ball milling for various times and the effect of mechanical alloying (MA) on the Sintering response of the composite compacts was investigated. The densification, microstructure, hardness and electrical conductivity after Solid Phase Sintering (SPS) and liquid Phase Sintering (LPS) were examined. It was shown that the microstructure of mechanically alloyed powder profoundly influence the Sintering response, i.e. a meaningful relationship between the Sintering kinetics and the milling time was observed. It is suggested that MA disintegrates the W–W particle networks and increases the contribution of Solid Phase Sintering (SPS) of nanostructured Cu and W particles on the densification. Higher hardness and conductivity were achieved by prolonged MA and SPS, indicating a lower W–W contiguity of the milled powders compared with the conventionally prepared W–Cu composite. On the other hand, depression of the melting temperature of copper up to 145 °C was noticed by affording a prolonged MA. The lower melting temperature and finer distribution of the Cu particles in the W matrix enhanced the densification during LPS and improved the homogeneity and properties of the final product.

  • Solid state and liquid Phase Sintering of mechanically activated W–20 wt.% Cu powder mixture
    Journal of Alloys and Compounds, 2008
    Co-Authors: Mohammad H Maneshian, A Simchi
    Abstract:

    Abstract W–20 wt.% Cu powder mixture was mechanically alloyed by high-energy ball milling for various times and the effect of mechanical alloying (MA) on the Sintering response of the composite compacts was investigated. The densification, microstructure, hardness and electrical conductivity after Solid Phase Sintering (SPS) and liquid Phase Sintering (LPS) were examined. It was shown that the microstructure of mechanically alloyed powder profoundly influence the Sintering response, i.e. a meaningful relationship between the Sintering kinetics and the milling time was observed. It is suggested that MA disintegrates the W–W particle networks and increases the contribution of Solid Phase Sintering (SPS) of nanostructured Cu and W particles on the densification. Higher hardness and conductivity were achieved by prolonged MA and SPS, indicating a lower W–W contiguity of the milled powders compared with the conventionally prepared W–Cu composite. On the other hand, depression of the melting temperature of copper up to 145 °C was noticed by affording a prolonged MA. The lower melting temperature and finer distribution of the Cu particles in the W matrix enhanced the densification during LPS and improved the homogeneity and properties of the final product.

Xinxin Qu - One of the best experts on this subject based on the ideXlab platform.

  • electrochemical properties of titanium based hydrogen storage alloy prepared by Solid Phase Sintering
    International Journal of Hydrogen Energy, 2010
    Co-Authors: Meng Yang, Xiangyu Zhao, Yi Ding, Xinxin Qu
    Abstract:

    Abstract The structure and electrochemical properties of titanium-based hydrogen storage alloy prepared by Solid Phase Sintering at 1123 K were investigated. The result of X-ray diffraction (XRD) showed that the sintered alloy mainly consists of Ti 2 Ni Phase coexisting with TiNi, TiNi 3 and Ni Phases. The alloy had a maximum discharge capacity of 205 mAh/g at a discharge current density of 60 mA/g and showed a discharge capacity of 146 mAh/g at 150 mA/g. The results of linear polarization (LP) and potential-step measurement presented that the exchange current density and hydrogen diffusion efficient of the alloy were 100 mA/g and 4.2 × 10 −9  cm 2 /s, respectively. The electrochemical performance of the alloy could be effectively improved by using Solid Phase Sintering.

G J Chen - One of the best experts on this subject based on the ideXlab platform.

  • study on the Solid Phase Sintering of the nano structured heavy tungsten alloy powder
    Journal of Alloys and Compounds, 2007
    Co-Authors: J S C Jang, L J Chang, G J Chen
    Abstract:

    Abstract Recently, the high performance W–Ni–Fe–Co heavy tungsten alloy has become as the major core material of armor piercing ammunition. Since the melting temperature of tungsten element is too high to be fabricated by the melting process, that the W–Ni–Fe–Co alloy only can be synthesized by powder metallurgy process. In this study, two compositions of alloy powders, 93W–3Ni–2Fe–2Co and 93W–3.5Ni–1.5Fe–2Co, were selected for investigating their microstructure and mechanical properties after Solid-Phase Sintering. These pre-alloyed powders with crystal cell size about 16 nm were synthesized by mechanical alloying (MA) the mixture of appropriate composition of pure elements in the Spex mill for 8 h. Then, the MA powders were compressed by cold isostatic pressing (CIP) and vacuum sintered at various temperature below 1400 °C for different time. Microstructure characterization of the sintered tungsten heavy alloys was conducted by means of SEM with EDS capability, X-ray diffraction (XRD), and TEM techniques. The result reveals that the microstructure of these sintered alloys was found to consist of the tungsten matrix Phase and the Fe–Ni Solid solution Phase. The hardness of these sintered tungsten heavy alloy presents a trend with increasing Sintering temperature and Sintering time.

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

  • Solid state and liquid Phase Sintering of mechanically activated w 20 wt cu powder mixture
    Journal of Alloys and Compounds, 2008
    Co-Authors: Mohammad H Maneshian, A Simchi
    Abstract:

    Abstract W–20 wt.% Cu powder mixture was mechanically alloyed by high-energy ball milling for various times and the effect of mechanical alloying (MA) on the Sintering response of the composite compacts was investigated. The densification, microstructure, hardness and electrical conductivity after Solid Phase Sintering (SPS) and liquid Phase Sintering (LPS) were examined. It was shown that the microstructure of mechanically alloyed powder profoundly influence the Sintering response, i.e. a meaningful relationship between the Sintering kinetics and the milling time was observed. It is suggested that MA disintegrates the W–W particle networks and increases the contribution of Solid Phase Sintering (SPS) of nanostructured Cu and W particles on the densification. Higher hardness and conductivity were achieved by prolonged MA and SPS, indicating a lower W–W contiguity of the milled powders compared with the conventionally prepared W–Cu composite. On the other hand, depression of the melting temperature of copper up to 145 °C was noticed by affording a prolonged MA. The lower melting temperature and finer distribution of the Cu particles in the W matrix enhanced the densification during LPS and improved the homogeneity and properties of the final product.

  • Solid state and liquid Phase Sintering of mechanically activated W–20 wt.% Cu powder mixture
    Journal of Alloys and Compounds, 2008
    Co-Authors: Mohammad H Maneshian, A Simchi
    Abstract:

    Abstract W–20 wt.% Cu powder mixture was mechanically alloyed by high-energy ball milling for various times and the effect of mechanical alloying (MA) on the Sintering response of the composite compacts was investigated. The densification, microstructure, hardness and electrical conductivity after Solid Phase Sintering (SPS) and liquid Phase Sintering (LPS) were examined. It was shown that the microstructure of mechanically alloyed powder profoundly influence the Sintering response, i.e. a meaningful relationship between the Sintering kinetics and the milling time was observed. It is suggested that MA disintegrates the W–W particle networks and increases the contribution of Solid Phase Sintering (SPS) of nanostructured Cu and W particles on the densification. Higher hardness and conductivity were achieved by prolonged MA and SPS, indicating a lower W–W contiguity of the milled powders compared with the conventionally prepared W–Cu composite. On the other hand, depression of the melting temperature of copper up to 145 °C was noticed by affording a prolonged MA. The lower melting temperature and finer distribution of the Cu particles in the W matrix enhanced the densification during LPS and improved the homogeneity and properties of the final product.

Jan Melkebeek - One of the best experts on this subject based on the ideXlab platform.