The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform

Yoshimi Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • Fabrication of Al-Based Composites by Centrifugal Mixed-Powder Method and Their Application for Grinding Wheels
    Journal of Materials Engineering and Performance, 2019
    Co-Authors: Yoshimi Watanabe, Hisashi Sato, Takayasu Sugiura, Hideaki Tsuge
    Abstract:

    In this study, Al-based metal matrix composite (MMC) with diamond and cBN abrasive grains was fabricated by a centrifugal mixed-Powder Method (CMPM). Two types of CMPM experiments with and without consolidated part were carried out. It was found that the MMC dispersed with diamond and cBN abrasive grains can be successfully fabricated by CMPM. In case of CMPM without consolidated part, the homogeneous distribution of the abrasive grains along hoop direction in the MMC could not be achieved due to slumping of mixed-Powder by gravity. On the other hand, modified CMPM using consolidated part could fabricate a MMC with uniform distribution of abrasive grains along hoop direction. Grinding wheels were manufactured using fabricated MMC samples, and drilling experiments were carried out on carbon fiber reinforced plastic (CFRP). It was found that the better drilling performance was found for the Al/Diamond grinding wheel rather than Al/cBN grinding wheel. Therefore, it can be concluded that the grinding wheel was not subjected at high temperature even though the drilling was carried out under dry condition.

  • Formation of compositional gradient in Al/SiC FGMs fabricated under huge centrifugal forces using solid-particle and mixed-Powder Methods
    Ceramics International, 2019
    Co-Authors: Saifulnizan Jamian, Yoshimi Watanabe, Hisashi Sato
    Abstract:

    Abstract Formations of graded distribution of SiC ceramic particles within the hollow cylindrical shaped Al/SiC functionally graded materials (FGMs) fabricated by centrifugal solid-particle Method (CSPM) and centrifugal mixed-Powder Method (CMPM) under huge centrifugal force are experimentally and theoretically investigated. The movement of SiC ceramic particles in viscous liquid under centrifugal force is explained based on Stoke's law. The effect of compositional gradient of particles on viscosity is taken into account. Also, the effect of temperature distribution on viscosity and density are considered. A computer code to simulate the formation of compositional gradient in the Al/SiC FGMs fabricated by CSPM and CMPM is developed. From the results, it is found that the volume fraction of SiC ceramic particles can be graded from the inner to the outer surface of hollow cylindrical shaped Al/SiC FGMs by CSPM. Meanwhile by CMPM, the SiC ceramic particles can be dispersed on the outer surface of hollow cylindrical shaped Al/SiC FGMs. The graded distribution in Al/SiC FGMs under huge centrifugal force is found to be significantly affected by the mold temperature but less affected by the temperature of molten Al and casting atmosphere.

  • Joining of AlN and Al with Compositional Graded Layer by Centrifugal Mixed-Powder Method
    Materials Science Forum, 2018
    Co-Authors: Yoshimi Watanabe, Masaki Murase, Hisashi Sato, Hideaki Tsukamoto
    Abstract:

    In this study, joining of AlN and Al with compositional graded layer is made by centrifugal mixed-Powder Method (CMPM). The mixed-Powder of AlN particles and Al particles is inserted into a spinning mold with bulk-shaped AlN, and then molten Al is poured into the spinning mold with the mixed-Powder and bulk-shaped AlN. As a result, the molten Al penetrates into the space between the mixed-Powder by the centrifugal force, and at the same time, the Al particles can be melted by heat from the molten Al. Then AlN and Al can be joined with compositional graded layer after solidification. Micromechanics-based analysis is also employed to understand the thermal stress relaxation by the compositional graded layer.

  • Effects of Particle Size on Fabrication of Al-TiO2 Functionally Graded Materials by Centrifugal Mixed-Powder Method
    Materials Science Forum, 2016
    Co-Authors: Hisashi Sato, Motoko Yamada, Junya Maeda, Yoshimi Watanabe
    Abstract:

    As one of processing Methods of functionally graded materials (FGMs), centrifugal mixed-Powder Method has been proposed. The centrifugal mixed-Powder Method is the casting process combined of centrifugal casting and Powder metallurgy. This processing Method has advantage that fine ceramics-particles, whose wettability with matrix melt is low, can be compounded into metallic material. However, effects of particle size on microstructure and mechanical properties of the FGMs fabricated by the centrifugal mixed-Powder Method are unclear. In this study, two kinds of Al-TiO2 FGMs rings are fabricated by the centrifugal mixed-Powder Method. One contains TiO2 particles having similar diameter with Al matrix particles (hereafter, small different-size (SD) TiO2 particles), and the other one compounds TiO2 particles with much smaller diameter than Al matrix particles (hereafter, large different-size (LD) TiO2 particles). In case of the Al-TiO2 FGMs ring containing SD-TiO2 particles, the TiO2 particles are homogeneously dispersed in Al matrix on outer surface of the ring. On the other hand, the TiO2 particles in the Al-TiO2 FGMs ring with LD-TiO2 particles are distributed along grain boundary of Al matrix. Moreover, Vickers-hardness and wear resistance around outer surface of the Al-TiO2 FGMs ring containing the SD-TiO2 particles is higher than that of the Al-TiO2 FGMs ring with LD-TiO2 particles. Since Al particles in the mixed-Powder with LD-TiO2 particles are surrounded by the TiO2 particles, the Al particles can be hardly melted by heat of molten Al at casting process. As a result, the Al-TiO2 FGMs ring with LD-TiO2 particles has low hardness and wear resistance. Therefore, it is found that TiO2 particles having similar diameter with Al matrix particles are more suitable for fabrication of the Al-TiO2 FGMs rings.

  • Fabrication of Metal-Based Functionally Graded Grinding Wheel by a Centrifugal Mixed-Powder Method
    Materials Science Forum, 2012
    Co-Authors: Eri Miura-fujiwara, Hisashi Sato, Motoko Yamada, Yoshimi Watanabe
    Abstract:

    Metal-bonded diamond grinding wheel was fabricated by a centrifugal mixed-Powder Method. The centrifugal mixed-Powder Method is a novel and effective casting process to obtain functionally graded material (FGM). At the beginning, we performed fundamental experiments using Al-Si alloy system for the purpose of knowing the migration behavior of mixed-Powder under centrifugal force. Al-Si hypereutectic alloyed-Powder or mixed-Powder of Al and Si particles was placed into the mold, and then Al molten metal was cast under a centrifugal force. Cross sectional microstructure observation and quantitative analysis of Si content were conducted using an electron probe microanalyzer. Amount of Si decreased with receding from a mixed-Powder region. Si concentration gradient in the sample fabricated Al-Si Powder was smaller than the one fabricated using mixed-Powder of Al and Si particles. Subsequently, φ 20 mm Cu/diamond grinding wheel was fabricated by the casting Method. Graded diamond distribution was successfully obtained.

Hisashi Sato - One of the best experts on this subject based on the ideXlab platform.

  • Fabrication of Al-Based Composites by Centrifugal Mixed-Powder Method and Their Application for Grinding Wheels
    Journal of Materials Engineering and Performance, 2019
    Co-Authors: Yoshimi Watanabe, Hisashi Sato, Takayasu Sugiura, Hideaki Tsuge
    Abstract:

    In this study, Al-based metal matrix composite (MMC) with diamond and cBN abrasive grains was fabricated by a centrifugal mixed-Powder Method (CMPM). Two types of CMPM experiments with and without consolidated part were carried out. It was found that the MMC dispersed with diamond and cBN abrasive grains can be successfully fabricated by CMPM. In case of CMPM without consolidated part, the homogeneous distribution of the abrasive grains along hoop direction in the MMC could not be achieved due to slumping of mixed-Powder by gravity. On the other hand, modified CMPM using consolidated part could fabricate a MMC with uniform distribution of abrasive grains along hoop direction. Grinding wheels were manufactured using fabricated MMC samples, and drilling experiments were carried out on carbon fiber reinforced plastic (CFRP). It was found that the better drilling performance was found for the Al/Diamond grinding wheel rather than Al/cBN grinding wheel. Therefore, it can be concluded that the grinding wheel was not subjected at high temperature even though the drilling was carried out under dry condition.

  • Formation of compositional gradient in Al/SiC FGMs fabricated under huge centrifugal forces using solid-particle and mixed-Powder Methods
    Ceramics International, 2019
    Co-Authors: Saifulnizan Jamian, Yoshimi Watanabe, Hisashi Sato
    Abstract:

    Abstract Formations of graded distribution of SiC ceramic particles within the hollow cylindrical shaped Al/SiC functionally graded materials (FGMs) fabricated by centrifugal solid-particle Method (CSPM) and centrifugal mixed-Powder Method (CMPM) under huge centrifugal force are experimentally and theoretically investigated. The movement of SiC ceramic particles in viscous liquid under centrifugal force is explained based on Stoke's law. The effect of compositional gradient of particles on viscosity is taken into account. Also, the effect of temperature distribution on viscosity and density are considered. A computer code to simulate the formation of compositional gradient in the Al/SiC FGMs fabricated by CSPM and CMPM is developed. From the results, it is found that the volume fraction of SiC ceramic particles can be graded from the inner to the outer surface of hollow cylindrical shaped Al/SiC FGMs by CSPM. Meanwhile by CMPM, the SiC ceramic particles can be dispersed on the outer surface of hollow cylindrical shaped Al/SiC FGMs. The graded distribution in Al/SiC FGMs under huge centrifugal force is found to be significantly affected by the mold temperature but less affected by the temperature of molten Al and casting atmosphere.

  • Joining of AlN and Al with Compositional Graded Layer by Centrifugal Mixed-Powder Method
    Materials Science Forum, 2018
    Co-Authors: Yoshimi Watanabe, Masaki Murase, Hisashi Sato, Hideaki Tsukamoto
    Abstract:

    In this study, joining of AlN and Al with compositional graded layer is made by centrifugal mixed-Powder Method (CMPM). The mixed-Powder of AlN particles and Al particles is inserted into a spinning mold with bulk-shaped AlN, and then molten Al is poured into the spinning mold with the mixed-Powder and bulk-shaped AlN. As a result, the molten Al penetrates into the space between the mixed-Powder by the centrifugal force, and at the same time, the Al particles can be melted by heat from the molten Al. Then AlN and Al can be joined with compositional graded layer after solidification. Micromechanics-based analysis is also employed to understand the thermal stress relaxation by the compositional graded layer.

  • Effects of Particle Size on Fabrication of Al-TiO2 Functionally Graded Materials by Centrifugal Mixed-Powder Method
    Materials Science Forum, 2016
    Co-Authors: Hisashi Sato, Motoko Yamada, Junya Maeda, Yoshimi Watanabe
    Abstract:

    As one of processing Methods of functionally graded materials (FGMs), centrifugal mixed-Powder Method has been proposed. The centrifugal mixed-Powder Method is the casting process combined of centrifugal casting and Powder metallurgy. This processing Method has advantage that fine ceramics-particles, whose wettability with matrix melt is low, can be compounded into metallic material. However, effects of particle size on microstructure and mechanical properties of the FGMs fabricated by the centrifugal mixed-Powder Method are unclear. In this study, two kinds of Al-TiO2 FGMs rings are fabricated by the centrifugal mixed-Powder Method. One contains TiO2 particles having similar diameter with Al matrix particles (hereafter, small different-size (SD) TiO2 particles), and the other one compounds TiO2 particles with much smaller diameter than Al matrix particles (hereafter, large different-size (LD) TiO2 particles). In case of the Al-TiO2 FGMs ring containing SD-TiO2 particles, the TiO2 particles are homogeneously dispersed in Al matrix on outer surface of the ring. On the other hand, the TiO2 particles in the Al-TiO2 FGMs ring with LD-TiO2 particles are distributed along grain boundary of Al matrix. Moreover, Vickers-hardness and wear resistance around outer surface of the Al-TiO2 FGMs ring containing the SD-TiO2 particles is higher than that of the Al-TiO2 FGMs ring with LD-TiO2 particles. Since Al particles in the mixed-Powder with LD-TiO2 particles are surrounded by the TiO2 particles, the Al particles can be hardly melted by heat of molten Al at casting process. As a result, the Al-TiO2 FGMs ring with LD-TiO2 particles has low hardness and wear resistance. Therefore, it is found that TiO2 particles having similar diameter with Al matrix particles are more suitable for fabrication of the Al-TiO2 FGMs rings.

  • Fabrication of Metal-Based Functionally Graded Grinding Wheel by a Centrifugal Mixed-Powder Method
    Materials Science Forum, 2012
    Co-Authors: Eri Miura-fujiwara, Hisashi Sato, Motoko Yamada, Yoshimi Watanabe
    Abstract:

    Metal-bonded diamond grinding wheel was fabricated by a centrifugal mixed-Powder Method. The centrifugal mixed-Powder Method is a novel and effective casting process to obtain functionally graded material (FGM). At the beginning, we performed fundamental experiments using Al-Si alloy system for the purpose of knowing the migration behavior of mixed-Powder under centrifugal force. Al-Si hypereutectic alloyed-Powder or mixed-Powder of Al and Si particles was placed into the mold, and then Al molten metal was cast under a centrifugal force. Cross sectional microstructure observation and quantitative analysis of Si content were conducted using an electron probe microanalyzer. Amount of Si decreased with receding from a mixed-Powder region. Si concentration gradient in the sample fabricated Al-Si Powder was smaller than the one fabricated using mixed-Powder of Al and Si particles. Subsequently, φ 20 mm Cu/diamond grinding wheel was fabricated by the casting Method. Graded diamond distribution was successfully obtained.

Sohan Singh - One of the best experts on this subject based on the ideXlab platform.

  • Thermal Expansion of ZrC From 120 to 300 K by an X‐Ray Powder Method
    Journal of the American Ceramic Society, 2006
    Co-Authors: Ebrahim Rahimzadeh, Narayan R. Joshi, Sohan Singh
    Abstract:

    Thermal expansion of ZrC, which has the NaCI type structure, was determined from, 120 to 300 K by a Powder X-ray diffraction Method. The lattice parameter was measured precisely using a specially designed D-shaped symmetrical back-reflection-focusing camera with the specimen hanging from a cryoflask in the vacuum chamber outside the camera on the Rowland circle. The average coefficient of linear thermal expansion of ZrC in this temperature range is 6.22 x 10-6/K. The Zr/C ratio was 0.993.

Zaiji Zhan - One of the best experts on this subject based on the ideXlab platform.

  • preparation of graphene nanoplatelets copper composites by a modified semi Powder Method and their mechanical properties
    Journal of Alloys and Compounds, 2016
    Co-Authors: Dandan Zhang, Zaiji Zhan
    Abstract:

    Abstract A modified semi-Powder Method was adopted to fabricate graphene nanoplatelets (GNPs)-copper composites in the present study. Electroless Cu and Ni plating were firstly performed on the surface of GNPs before semi-Powder mixing to improve wettability of GNPs. The main structure of GNPs was maintained after the plating process. Microstructure studies showed both of 0.5 vol.% copper-plated and nickel-plated GNPs (Cu-GNPs and Ni-GNPs) were uniformly distributed and well bonded with the Cu matrix. The electroless plating improved the mutual disperse of GNPs and the Cu matrix. Compared with pure Cu, the composite with addition of 0.5% Cu-GNPs exhibited an increase of 49.1% in yield strength. Benefiting from better dispersion and stronger interfacial bonding, the increase of 64.5% in yield strength was obtained in the 0.5% Ni-GNPs/Cu composite. The strengthening mechanisms, including grain refinement, thermal mismatch and load transfer were carefully discussed.

S. Kalainathan - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis, growth and characterization of organic nonlinear optical 3-(4-fluorophenyl)-1-(4-methoxyphenyl) single crystal grown by vertical Bridgman technique
    Organic Electronics, 2020
    Co-Authors: K. Arunkumar, S. Kalainathan
    Abstract:

    Abstract Single crystal of organic nonlinear optical material 3-(4-Fluorophenyl)-1-(4-methoxyphenyl) (FMP) was grown with the help of single walled glass ampoule in vertical Bridgman technique. The structural analysis confirmed the cell parameters and crystallinity of the single crystal with the space group of Pbca. The presences of desired components in the single crystal were confirmed by the NMR spectrum. The lower cut off wavelength of the single crystal was observed at 423 nm from the absorption spectra of the single crystal. The electrical property of grown single crystal was studied by measuring the dielectric constant and dielectric loss. The surface hardness test and amount of damage caused by incident laser beam on the surface of the single crystal determined the mechanical strength of the crystal. The FMP single crystal was found to exhibit negative photoconductive nature. The etch pit density and non-linear optical properties were determined by etching measurement and by observation of green light in Kurtz-Perry Powder Method. The grown crystal was studied thermal stability and melting point with TGA-DSC analysis.