Thermal Conductivities of β-SiAlONs by Mechanically Activated Combustion Synthesis

2008 ◽  
Vol 403 ◽  
pp. 139-140 ◽  
Author(s):  
R. Sivakumar ◽  
K. Aoyagi ◽  
T. Watanabe ◽  
T. Akiyama
Keyword(s):  
Thermal Conductivity ◽  
Combustion Synthesis ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Thermal Conductivities

–sialons (Si6-zAlzOzN8-z, z=3) synthesized by mechanically activated combustion synthesis (MA-CS) at a low N2 pressure of 1 MPa, were sintered by Spark Plasma Sintering (SPS) and thermal conductivity was measured at room temperatures. Specimens were fully densified at 1600oC for 10 mins. and showed only –sialon phases confirmed by x-ray diffraction patterns though un-reacted Si was present as impurities after MA-CS. Thermal conductivities increased with sintering temperature and had a maximum value 5.49 W m-1 K-1 for specimens sintered at 1700oC.

Spark Plasma Sintering of Paper-Derived Ti3AlC2-Based Composites: Influence of Sintering Temperature

2021 ◽  
Vol 1016 ◽  
pp. 1790-1796
Author(s):  
Maxim Syrtanov ◽  
Egor Kashkarov ◽  
Tatyana Murashkina ◽  
Nahum Travitzky
Keyword(s):  
Phase Composition ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Total Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbide Phases ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Scanning Electron

This paper describes the influence of sintering temperature on phase composition and microstructure of paper-derived Ti3AlC2 composites fabricated by spark plasma sintering. The composites were sintered at 100 MPa pressure in the temperature range of 1150-1350 °C. Phase composition and microstructure were analyzed by X-ray diffraction and scanning electron microscopy, respectively. The multiphase structure was observed in the sintered composites consisting of Ti3AlC2, Ti2AlC, TiC and Al2O3 phases. The decomposition of the Ti3AlC2 phase into Ti2AlC and TiC carbide phases was observed with temperature rise. The total content of Ti3AlC2 and Ti2AlC phases was reduced from 84.5 vol.% (1150 °C) to 69.5 vol.% (1350 °C). The density of composites affected by both the content of TiC phase and changes in porosity.

Effect of the Dwell Temperature on Spark Plasma Sintered CaCu3Ti4O12

2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lattice Parameter ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Scanning Electron

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.

Fabrication of Ti-Based Biodegradable Material Composites Prepared by Spark Plasma Sintering Method

2010 ◽  
Vol 654-656 ◽  
pp. 2158-2161 ◽  
Author(s):  
Eri Miura-Fujiwara ◽  
Takeshi Teramoto ◽  
Hisashi Sato ◽  
Equo Kobayashi ◽  
Yoshimi Watanabe
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Holding Time ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Porous Ti ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method

This study aims at producing porous Ti filled with biodegradable materials for biomedical implants by means of spark plasma sintering method (SPS). To improve bone fixation and to obtain appropriate Young’s modulus as a medical implant material, we applied -tri calcium phosphate (-TCP) to the Ti-based composite. Ti/-TCP powder mixtures were sintered by SPS under applied stress of 45MPa with various temperatures and holding time. Vickers hardness (Hv) of obtained composite increased with increasing the holding time up to 10 min, and saturated hardness was approximately 750 Hv, which is extremely higher than that of bulk Ti. Hardness also increased as sintering temperature increased up to 1473 K. From the results of microstructure observations by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDXS), O- and P- containing Ti surrounded around Ti particle, and O diffused into Ti particle to a certain extent. X-ray diffraction results indicated several kinds of Ti-O and/or Ti-P formed in the specimen. Results indicated that it is the brittle phases formed during sintering that increased the hardness.

Preparation and Properties of Spark Plasma Sintered AlN/BN Nano-Composites

2007 ◽  
Vol 352 ◽  
pp. 197-200
Author(s):  
Mei Juan Li ◽  
Lian Meng Zhang ◽  
Z.D. Wei ◽  
Qiang Shen ◽  
Dong Ming Zhang
Keyword(s):  
Thermal Conductivity ◽  
Chemical Process ◽  
Bending Strength ◽  
Nano Composites ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

Nano-sized turbostritic-BN (t-BN) was fabricated through chemical process using boric acid and urea in this work. By the same method, the AlN powders coated with nano-BN were prepared too. The results of X-ray diffraction (XRD) and transmission electron microscope (TEM) revealed that nano-sized t-BN was synthesized at about 600°C in nitrogen gas and it surrounded the surface of AlN particles. High-density AlN/BN nano-composites were fabricated spark plasma sintering (SPS). Microstructure and properties of AlN/BN nano-composites (5~30vol% BN) were investigated. The h-BN flake particles were homogenously dispersed at AlN grain boundaries and within grains in the AlN/BN composites. A little nano-BN additions significantly improved the bending strength of the nano-composites. However, the bending strength was decreased with the BN content increasing. The thermal conductivity of AlN/BN nano-composites was investigated too.

Preparation and Properties of Up-Conversion Luminescent NaYF4:Yb3+, Er3+ Ceramics

2016 ◽  
Vol 848 ◽  
pp. 262-271
Author(s):  
Wen Yan Cheng ◽  
Shi Jia Gu ◽  
Bei Ying Zhou ◽  
Lian Jun Wang ◽  
Wei Luo ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Sintering Temperature ◽  
Holding Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Crystal Phases ◽  
Co Doped

A series of ytterbium and erbium co-doped sodium yttrium fluoride (NaYF4:Yb3+, Er3+) ceramics have been successfully prepared by pressureless sintering. The ceramic samples were characterized by X-ray diffraction (XRD), photoluminescence (PL), density and field emission scanning electron microscope (FESEM). The results showed that the phases of the NaYF4:Yb3+, Er3+ ceramic samples transformed when the sintering temperature was changed. The ceramic samples sintered below 600 oC contained both cubic α-NaYF4:Yb3+, Er3+ and hexagonal β-NaYF4:Yb3+, Er3+. The sample sintered at 600oC is the pure hexagonal β-NaYF4:Yb3+, Er3+. When the sintering temperature is above 600 oC, the ceramic samples present the α-NaYF4:Yb3+, Er3+ again. The fluorescence intensity increased firstly and then decreased with the sintering temperature increasing. The luminous intensity of the sample sintered at 600 oC was the highest. The densities of as-prepared ceramic sample increased with the sintering temperature rising. The samples sintered at 600 oC with different holding time possessed the similar crystal phases (β-NaYF4:Yb3+, Er3+) and fluorescence intensity. As the holding time increased, the densities of the samples increased. To obtain more dense ceramics, the ceramics using β-NaYF4:Yb3+, Er3+ powders were prepared by spark plasma sintering (SPS). The maximum relative density reached 97%.

scholarly journals Properties of TiC and TiN Reinforced Alumina–Zirconia Composites Sintered with Spark Plasma Technique

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1220 ◽  
Author(s):  
Magdalena Szutkowska ◽  
Sławomir Cygan ◽  
Marcin Podsiadło ◽  
Jolanta Laszkiewicz-Łukasik ◽  
Jolanta Cyboroń ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
New Type ◽  
Diffraction Patterns

In this paper, Al2O3–ZrO2 composites with an addition of 20 wt% TiN and 10 wt% TiC were modified. The addition of zirconia in a range from 2 to 5 wt% of the monoclinic phase and 10 wt% of Y2O3 stabilised ZrO2 affected the mechanical properties of the composites. A new type of sintering technique—the spark plasma sintering (SPS) method—within a temperature range from 1575 °C to 1675 °C, was used. Vickers hardness, apparent density, wear resistance and indentation fracture toughness KIC(HV) were evaluated at room temperature. An increase of the sintering temperature resulted in an improvement of Vickers hardness and an increase of the fracture toughness of the tested composites. The tribological properties of the samples were tested using the ball-on-disc method. The friction coefficient was in a range from 0.31 to 0.55, depending on the sintering temperature. An enhancement of the specific wear rate was dependent on the sintering temperature. The mechanical properties of the samples sintered by pressureless sintering (PS) were compared. X-ray diffraction patterns were presented in order to determine the phase composition. SEM microstructure of the tested composites sintered at different temperatures was observed.

Structure and Magnetic Properties of Spark Plasma Sintered NdFeB

2015 ◽  
Vol 1112 ◽  
pp. 27-31
Author(s):  
Toto Sudiro ◽  
Didik Aryanto ◽  
Nenen Rusnaeni Djauhari ◽  
Citra Wara Br Sinuraya ◽  
Syahrul Humaidi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Carbon Paper ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Product ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
Effects Of Temperature ◽  
Diffraction Patterns

A spark plasma sintering technique was used to consolidate NdFeB compacts at four different temperatures as 750°C, 850°C, 950°C and 1030°C. The surface of specimens was polished to remove the carbon paper on the surface of NdFeB compacts by using SiC paper for up to #1500 in grit. The polished NdFeB compacts were then magnetized by using impulse magnetizer K-series. In this study, the effects of temperature on the structure and magnetic properties of NdFeB magnet were studied. The results show that depending on the fabrication temperature, the X-ray diffraction patterns of NdFeB compacts are distinct. This suggests that the structure of NdFeB compacts is changed with increase in fabrication temperature. Meanwhile, the remanance Br and energy product BH(max) of NdFeB magnets tend to decrease as fabrication temperature increase.

Effect of the Pt Addition on the Ni-Alloy Powder during Spark Plasma Sintering

2013 ◽  
Vol 746 ◽  
pp. 220-228
Author(s):  
Jonathan C.G. Sanchez ◽  
Jose A. Andraca ◽  
David V. Jaramillo ◽  
Fernando L. Juárez
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Homogeneous Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Consolidation ◽  
Plasma Sintering ◽  
Ni Alloy ◽  
Spark Plasma ◽  
Short Time

Spark plasma sintering was carried out to densify Ni-alloy doped with Pt powder at temperatures ranging between 1273 and 1323 K in order to obtain a variety of microstructures. Homogeneous distribution Pt and full densification were achieved in a short time, and the overall processing time not was exceeding 30 min via SPS process. Phase constitutions and microstructures and porosity evaluation were investigated by using scanning electron microscopy, chemical analysis and X-ray diffraction. It was found that two new phases ζ-PtAl2 and α-NiPt (Al). The set conditions are very promising from an energy-saving viewpoint; total powder consolidation was obtained per a decrease of 200 °C in the sintering temperature by using spark plasma sintering.

Densification of Zirconia–Hydroxyapatite Ceramics Without Phase Changes

2006 ◽  
Vol 309-311 ◽  
pp. 1141-1144 ◽  
Author(s):  
Erik Adolfsson ◽  
Z. Shen
Keyword(s):  
Hot Isostatic Pressing ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
Structural Water ◽  
X Ray ◽  
Plasma Sintering ◽  
Hydroxyapatite Ceramics ◽  
Different Temperatures ◽  
Spark Plasma ◽  
Diffraction Patterns

Zirconia-hydroxyapatite (40-60 vol%) composites were sintered at different temperatures in air. The x-ray diffraction patterns of the sintered composites showed that hydroxyapatite began to decompose to tricalcium phosphate even below 950°C. The decomposition of hydroxyapatite also involved release of structural water, which was studied using thermogravimetric analysis. By reducing the loss of structural water from the hydroxyapatite, the phase stability of the hydroxyapatite could be increased. This allowed higher temperatures to be used during the densification process where dense composites without any detectable reactions where produced by hot isostatic pressing at 1200°C as well as with spark plasma sintering at 1100°C.

scholarly journals The Effect of Reactive Electric Field-Assisted Sintering of MoS2/Bi2Te3 Heterostructure on the Phase Integrity of Bi2Te3 Matrix and the Thermoelectric Properties

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 53
Author(s):  
Yanan Wang ◽  
Cédric Bourgès ◽  
Ralph Rajamathi ◽  
C. Nethravathi ◽  
Michael Rajamathi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electric Field ◽  
Hydrothermal Reaction ◽  
X Ray Diffraction ◽  
Nanocomposite Structure ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Field Assisted Sintering

In this work, a series of Bi2Te3/X mol% MoS2 (X = 0, 25, 50, 75) bulk nanocomposites were prepared by hydrothermal reaction followed by reactive spark plasma sintering (SPS). X-ray diffraction analysis (XRD) indicates that the native nanopowders, comprising of Bi2Te3/MoS2 heterostructure, are highly reactive during the electric field-assisted sintering by SPS. The nano-sized MoS2 particles react with the Bi2Te3 plates matrix forming a mixed-anion compound, Bi2Te2S, at the interface between the nanoplates. The transport properties characterizations revealed a significant influence of the nanocomposite structure formation on the native electrical conductivity, Seebeck coefficient, and thermal conductivity of the initial Bi2Te3 matrix. As a result, enhanced ZT values have been obtained in Bi2Te3/25 mol% MoS2 over the temperature range of 300–475 K induced mainly by a significant increase in the electrical conductivity.

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