Nanostructured Ceramic Oxides Containing Ferrite Nanoparticles and Produced by Mechanical Milling.

2012 ◽  
Vol 1485 ◽  
pp. 71-76
Author(s):  
A. Huerta-Ricardo ◽  
K. Tsuchiya ◽  
T. Umemoto ◽  
H. A. Calderon
Keyword(s):  
Mechanical Milling ◽  
Magnetic Particles ◽  
Volume Fraction ◽  
Nanocrystalline Structure ◽  
Ceramic Materials ◽  
Matrix Composites ◽  
Vacuum Sintering ◽  
Ceramic Oxides ◽  
Plasma Sintering ◽  
Spark Plasma

ABSTRACTThis investigation deals with the production process and the characterization of ceramic materials consisting of magnetic particles in an insulating matrix. Composites made of magnetite particles (Fe3O4 or MgFe2O4) in a wüstite or magnesiowüstite matrix (FexO or Mg1-xFexO), respectively, have been produced by means of mechanical milling and spark plasma sintering. As-milled powders have a nanocrystalline structure in both systems. As a function of milling time, low energy milling gives rise to an increasingly higher volume fraction of wüstite in the FexO-Fe3O4 system while it promotes increasing amounts of magnesiowüstite (MgxFe1-xO). Sintering is performed from 673 to 1273 K in vacuum. Sintering at low temperatures allows retention of nanosized grains containing a fine dispersion of magnetic particles in a wüstite and magnesiowüstite matrix. Measurement of magnetic properties reflects the constitution of the sintered samples and the effect of grain size. It also allows determination of the transformation sequence both during mechanical milling and sintering

Nanocomposites in the Systems Fe1−xO-Fe3O4 and MgO-MgFe2O4 Produced by Mechanical Alloying

1999 ◽  
Vol 581 ◽  
Author(s):  
A. Huerta ◽  
H. A. Calderon ◽  
H. Yee-Madeira ◽  
M. Umemoto ◽  
K. Tsuchiya
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Mechanical Milling ◽  
Magnetic Particles ◽  
Milling Time ◽  
Volume Fraction ◽  
Low Energy ◽  
Nanocrystalline Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

ABSTRACTWtastite-magnetite and magnesia-magnesioferrite nanocrystalline ceramics have been prepared by mechanical milling and spark plasma sintering. As-milled powders have a nanocrystal-line structure in both systems. Low energy milling gives rise to an increasingly higher volume fraction of wfistite as a function of milling time in the Fe1−xO-Fe3O4 system. Similar results are obtained in the MgO-MgFe2O4 system with increasingly larger amounts of MgFe2O4 produced by milling. Composites of magnetic particles (Fe3O4 or MgFe2O4) in a nonconductive matrix (FeO or MgO, respectively) are found in the sintered samples. Measurement of magnetic properties can be used to determine conclusively the nature of the developed phases and the effect of grain size.

Production and Magnetic Properties of Nanocomposites made of Ferrites and Ceramic Matrices

2001 ◽  
Vol 703 ◽  
Author(s):  
H. A. Calderon ◽  
A. Huerta ◽  
M. Umemoto ◽  
K. Cornett
Keyword(s):  
Magnetic Properties ◽  
Magnetic Particles ◽  
Milling Time ◽  
Volume Fraction ◽  
Nanocrystalline Structure ◽  
Low Energy ◽  
Nanocrystalline Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Ceramic Matrices

ABSTRACTThis investigation deals with the production of materials containing a dispersion of magnetic nanoparticles in an insulating matrix. Such a distribution of magnetic centers is expected to absorb electromagnetic radiation in a range of wavelengths. Wüstite-magnetite and magnesiamagnesioferrite nanocrystalline ceramics have been prepared by mechanical milling and spark plasma sintering. As-milled powders have a nanocrystalline structure in both systems. Low energy milling gives rise to an increasingly higher volume fraction of wüstite as a function of milling time in the Fe1-xO-Fe3O4 system. Similar results are obtained in the MgO-MgFe2O4 system with increasingly larger amounts of MgFe2O4 produced by milling. Composites of magnetic particles (Fe3O4 or MgFe2O4) in a nonconductive matrix (FeO or MgO, respectively) are found in the sintered samples. Measurement of magnetic properties can be used to determine conclusively the nature of the developed phases and the effect of grain size.

Characterization and Production of Structurat Ceramics in the Systems Fe(1-X)O-Fe3O4 and MgO-MgFe2O4.

1999 ◽  
Vol 5 (S2) ◽  
pp. 810-811
Author(s):  
A. Huerta ◽  
R. Ordoñez ◽  
H.A. Calderon ◽  
M. Umemoto ◽  
K. Tsuchiya ◽  
...  
Keyword(s):  
Ceramic Materials ◽  
Grain Structure ◽  
Second Phase ◽  
Magnetic Recording Media ◽  
Mechanically Alloyed ◽  
Ceramic Oxides ◽  
Plasma Sintering ◽  
Structural Applications ◽  
Spark Plasma ◽  
Second Phases

Ceramic materials are widely studied for their high temperature structural applications. In many crystalline ceramics the range of solid solution decreases with temperature and thus precipitation of a second phase occurs. Thus, ceramics can be hardened by precipitation of second phases. However little is known regarding the effect of precipitation and nanocrystalline grain structure in the ductility of ceramic materials. On the other hand, oxide ceramics are under intense-investigation for their technological advantages in magnetization, dielectric response and chemical stability in such diverse uses as magnetic recording media, induction cores and microwave resonant circuits. This investigation has been undertaken to produce, characterize and measure the properties of ceramics that can be hardened by precipitation. The selected systems include Fe(1-x)O-Fe3 and MgO MgFe2O4. Mechanical milling is used to produce nanocrystalline ceramic oxides in the systems Fe(1-x)O-Fe3 and MgO-MgFe2O4 The mechanically alloyed powders are consolidated by means of spark plasma sintering (SPS) at temperatures ranging from 673 K to 1273 K and a pressure varying from 500 to 50 MPa in vacuum.

Study on Mechanical Alloying of TiB2 Particulate Reinforced Titanium Matrix Composites

2018 ◽  
Vol 875 ◽  
pp. 41-46 ◽  
Author(s):  
Yue Ying Li ◽  
Fu Wen Zhu ◽  
Zhen Liang Qiao
Keyword(s):  
Mechanical Alloying ◽  
Milling Time ◽  
Volume Fraction ◽  
Matrix Composites ◽  
Titanium Matrix ◽  
Titanium Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Powder Particles ◽  
Particulate Reinforced

TiB2 particulate reinforced titanium matrix composites were prepared by mechanical alloying and spark plasma sintering. Volume fraction of TiB2 powders in the composites are 5%, 10%, 15%. The effect of milling time and the volume fraction of reinforcement on microstructure and properties of the composites were studied. The results show that with increasing milling time, the size of powder particles decreases, quantity of them increases, and microstructure of the sintered samples becomes finer and more uniform. When milling time reaches 30h, the trend of powder agglomeration increases, the downward trend of the particle size becomes slowly. With the milling time, the density of titanium matrix composites is on the rise. The density of 10vol%TiB2 particulate reinforced titanium matrix composites can reach 4.799 g/cm3, with 30h milling time and sintering at 900°C. The density and hardness of the composites increase with increasing the volume fraction of TiB2. When the volume fraction of TiB2 is 15%, after milling 10h and sintered at 800°C, the density and hardness of the composites can reach 4.713g/cm3 and HV851.58.

Fabrication by SPS and Thermophysical Properties of High Volume Fraction SiCp/Al Matrix Composites

2006 ◽  
Vol 313 ◽  
pp. 171-176 ◽  
Author(s):  
X.F. Gu ◽  
Lian Meng Zhang ◽  
Mei Jun Yang ◽  
Dong Ming Zhang
Keyword(s):  
Thermophysical Properties ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
High Volume ◽  
High Volume Fraction ◽  
Matrix Composites ◽  
Sic Particles ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Al Matrix Composites

SiCp/Al composites containing high volume fraction of SiC particles were fabricated by spark plasma sintering (SPS), and their thermophysical properties, such as thermal conductivity (TC) and coefficient of thermal expansion (CTE), were characterized. High relative density (R-D) of composites was successfully achieved through the optimization of sintering parameters, such as sintering temperature, sintering pressure and heating rate. The measured TCs of SiCp/Al composites fabricated by SPS are higher than 195W/m.k, no matter the volume fraction of SiC particles is high or low as long as the R-D is higher than 95%. The measured CTEs of SiCp/Al composites are in good agreement with the estimated values based on Kerner,s model. The high volume fraction of SiCp/Al composites are a good candidate material to substitute for conventional thermal management materials in advanced electronic packages due to its tailorable thermophysical properties.

Synthesis of nanostructured metal (Fe, Al)-C60 composites

2010 ◽  
Vol 1276 ◽  
Author(s):  
I. I. Santana García ◽  
V. Garibay Febles ◽  
H. A. Calderon
Keyword(s):  
Raman Spectroscopy ◽  
Mechanical Milling ◽  
Volume Fraction ◽  
High Volume ◽  
X Ray Diffraction ◽  
Nanostructured Composite ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Show Evidence ◽  
Spark Plasma

AbstractComposites of M-2.5 mol. % Fullerene C60 composites (where M= Fe or Al) are prepared by mechanical milling and Spark Plasma Sintering (SPS). The SPS technique has been used to consolidate the resulting powders and preserve the massive nanostructure. Results of X-Ray Diffraction and Raman Spectroscopy show that larger milling balls (9.6 mm in diameter) produce transformation of the fullerene phase during mechanical milling. Alternatively smaller milling balls (4.9 mm in diameter) allow retention of the fullerene phase. SEM shows homogeneous powders with different particle sizes depending on milling times. Sintering produces nanostructured composite materials with different reinforcing phases including C60 fullerenes, diamonds and metal carbides. The presence of each phase depends characteristically on the energy input during milling. Transmission Electron Microscopy (TEM) and Raman Spectroscopy show evidence of the spatial distribution and nature of phases. Diamonds and carbides can be identified for the sintered Fe containing composites with a relatively high volume fraction.

Thermal Conductivity of Cubic Boron Nitride (cBN) Particle Dispersed Al Matrix Composites Fabricated by SPS

2016 ◽  
Vol 879 ◽  
pp. 2413-2418 ◽  
Author(s):  
Kiyoshi Mizuuchi ◽  
Kanryu Inoue ◽  
Yasuyuki Agari ◽  
Motohiro Tanaka ◽  
Takashi Takeuchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Volume Fraction ◽  
Cubic Boron Nitride ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Al Matrix Composites ◽  
Al Matrix Composite ◽  
Al Matrix

Cubic boron nitride (cBN) particle-dispersed-aluminum (Al) matrix composites were fabricated from the powder mixture composed of cBN, pure Al and Al-5mass% Si alloy in liquid and solid co-existent state by spark plasma sintering (SPS) process. Al/cBN composites were well consolidated by heating at a temperature range between 798 K and 876 K for 1.56 ks by SPS. Microstructures of the composites produced were examined by scanning electron microscopy and the reaction between the cBN particle and the Al matrix was not detected. The relative packing density of the Al/cBN composite was higher than 99 % in a volume fraction range of cBN up to 45 %. The thermal conductivity of the composite increased with increasing the cBN content in the composite in a volume fraction range of cBN between 35 and 45 vol. %. The highest thermal conductivity of 305 W/mK was obtained for Al matrix composite containing 45 vol.% cBN particles.

scholarly journals Sinterability and characterization of Ag/Al2O3 metal and ceramic matrix composites processed by mechanical milling

2020 ◽  
Vol 52 (3) ◽  
pp. 245-255
Author(s):  
Ramin Davodi ◽  
Mohammad Ardestani ◽  
Arqavan Kazemi
Keyword(s):  
Flexural Strength ◽  
Mechanical Milling ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
The Other ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Al2o3 Composite ◽  
Spark Plasma

In this research, the sinterability of Ag/Al2O3 milled powders with 10 and 90 wt%Ag were investigated. The powders were consolidated by two different processes including conventional and spark plasma sintering. The conventionally sintered composites with 90 wt%Ag were further densified by cold pressing and subsequent annealing at 700?C. The microstructural evaluations confirmed a fine dispersion of the constituents within the microstructure of the spark plasma sintered composites. Moreover, the results showed that the relative density, hardness, and flexural strength of the spark plasma sintered samples were much higher than those of the other samples. The hardness and flexural strength of Ag/10 wt%Al2O3 spark plasma sintered samples at 650?C were 146 HV and 264 MPa, respectively. However, unlike the composite with 90 wt%Ag, the applied sintering temperatures have not led to the synthesis of an Ag/90 wt% Al2O3 composite with the desired properties

Effect of Particle Shape on Dispersion Formation of Harmonic Microstructure of Si3N4-ZrO2

2016 ◽  
Vol 864 ◽  
pp. 47-51 ◽  
Author(s):  
Lydia Anggraini ◽  
Yuta Natsume ◽  
Kei Ameyama
Keyword(s):  
Mechanical Properties ◽  
Mechanical Milling ◽  
Bending Strength ◽  
Powder Processing ◽  
Ceramic Matrix Composites ◽  
Zirconia Ceramic ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Particle Shapes

Silicon nitride with 50 mass zirconia ceramic matrix composites were processed by mechanical milling (MM) followed by spark plasma sintering (SPS). Two different of Si3N4 particle shapes for create harmonic microstructure were investigated. The microstructure of Si3N4-ZrO2 with initial Si3N4 shape is like coin/flakes after MM for 144 ks was failed to create the harmonic microstructure after SPS. With another sphere shape of Si3N4 after MM for 144 ks, the harmonic microstructure could be formed after SPS. Thus, the initial powders shape of Si3N4 have an effect in the formation of harmonic microstructure could be fully achieved. The highest mechanical properties of Si3N4-ZrO2 are on the powders with mechanical milling time for 144 ks. The Si3N4 ceramic with homogeneous fine grains of ZrO2 dispersed on its surface was obtained, and the mechanical properties were improved. The Vickers hardness obtained on 144 ks is 1031 MPa and the bending strength is 262 MPa. The main factors explaining the improvement in the mechanical properties of Si3N4-ZrO2 are considered to be the porosity decrease caused by the particles shape and appropriate condition of powder processing i.e. MM and SPS.

In Situ TiB Reinforced Titanium Metal Matrix Composites Prepared by Spark Plasma Sintering

2005 ◽  
Vol 502 ◽  
pp. 189-194
Author(s):  
Yu Zhou ◽  
Hai Bo Feng ◽  
De Chang Jia
Keyword(s):  
Spark Plasma Sintering ◽  
Volume Fraction ◽  
Sintering Temperature ◽  
Matrix Composites ◽  
Titanium Matrix ◽  
Cubic Lattice ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Crystallographic Planes

In situ synthesized TiB reinforced titanium matrix composites of Ti-B and Ti-TiB2 systems have been prepared by spark plasma sintering at 800-1200 °C under 20 MPa for 5 min. The effects of sintering temperature and reinforcement volume fraction on flexural strength, Young’s modulus and fracture toughness of the composites were investigated. The in situ synthesized TiB reinforcements are randomly and uniformly distributed in titanium matrix. The TiB whiskers are aligned along [010] direction, and the crystallographic planes of the TiB needles are always of the type (100), (101) and (10 1) . The parallel TiB were observed in β-Ti grains in both of the investigated composites. The in situ TiB needle is likely to grow along [010] direction which is parallel to [111] direction of cubic lattice of β-Ti phase.

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