scholarly journals The Effect of SiC Content on Microstructure and Microwave Heating Rate of h-BN/SiC Ceramics Fabricated by Spark Plasma Sintering

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1909 ◽  
Author(s):  
Huilin Lun ◽  
Yi Zeng ◽  
Xiang Xiong ◽  
Lei Zhao ◽  
Dongling Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Relative Density ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Hexagonal Boron Nitride ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

Hexagonal boron nitride/silicon carbide (h-BN/SiC) ceramics were fabricated by a spark plasma sintering (SPS) method. Phase and microstructure of ceramics were characterized and observed, respectively, using the X-ray diffraction, scanning electron microscope and electron probe microanalysis. The effect of molar ratios of SiC to h-BN on the microstructure, relative density, hardness, thermal conductivity, and the heating rate by microwaves on the ceramics were investigated. The results showed that the orientation of flake-like h-BN was significantly influenced by SiC content in h-BN/SiC ceramics. With the increasing of SiC content, the h-BN flakes gradually became an isotropic distribution from the preferred orientation aligning in a SPS pressure direction. The relative density of h-BN/SiC ceramics was 97.6 ± 0.9% at a molar ratio of SiC to h-BN of 40/60 mol%. The preferential orientation of h-BN flakes contributed to a relatively high thermal conductivity along the SPS pressure direction, which was beneficial to increasing the heating rate of h-BN/SiC ceramics in microwave fields.

Fabrication of High Dense ZnSe Ceramic by Spark Plasma Sintering: The Effect of the Powder Process Method

2018 ◽  
Vol 281 ◽  
pp. 661-666
Author(s):  
Jia Lin Gao ◽  
Peng Liu ◽  
Jian Zhang ◽  
Xiao Dong Xu ◽  
Ding Yuan Tang
Keyword(s):  
Relative Density ◽  
Ball Milling ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Zinc Selenide ◽  
Plasma Sintering ◽  
Planetary Ball Milling ◽  
Spark Plasma ◽  
Process Method

Zinc Selenide ceramic was successfully fabricated by spark plasma sintering in the study. The ZnSe raw powders were handled with two different methods such as grinding and planetary ball milling, respectively. The relative density, microstructure and transmittance of the ZnSe ceramic sintered under the same sintering parameter with two type powders was investigated. The results shown that the performance of the powder processed by ball milling was more effective than that by grinding. Furthermore, the maximum relative density can reach 99.8% when the ZnSe powder treated by ball milling were sintered at 950 oC for 30 min with the heating rate of 10 oC/min under 100 MPa.

Microstructural Development of SiC Ceramics by Liquid-Phase Sintering with Spark Plasma Sintering Technique

2006 ◽  
Vol 510-511 ◽  
pp. 1022-1025 ◽  
Author(s):  
Mikinori Hotta ◽  
Junichi Hojo
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Liquid Phase Sintering ◽  
Molar Ratio ◽  
Microstructural Development ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
N2 Atmosphere ◽  
Average Grain Size ◽  
Spark Plasma

Sub-micron and nano-sized β-SiC powders were sintered with AlN and Y2O3 as sintering additives by spark plasma sintering (SPS). The sintered densities reached >95% of theoretical with a different molar ratio of AlN to Y2O3 at total amount of 10vol% and temperature of 1900oC for 10min in N2 atmosphere under a pressure of 30MPa. With increasing amount of the AlN additive, the size of SiC grains decreased and the shape changed from globular to columnar. The fully densified SiC at AlN:Y2O3=95:5mol% had an average grain size of 0.5-1µm and 50-100nm in diameter by using sub-micron and nano-sized SiC starting powders, respectively. Flexural strength of the specimen having grain size of 0.5-1µm was approximately 1200MPa at room temperature.

Preparation and Properties of ZrB2-Cu Composites by Spark Plasma Sintering

2012 ◽  
Vol 512-515 ◽  
pp. 739-743 ◽  
Author(s):  
S.Z. Zhu ◽  
D.L. Gong ◽  
Z. Fang ◽  
Q. Xu
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Volume Fraction ◽  
Sintering Temperature ◽  
High Electrical Conductivity ◽  
Particulate Reinforcement ◽  
Plasma Sintering ◽  
Spark Plasma

For high thermal conductivity and high electrical conductivity, copper is a good electrode material. The wearing resistance and spark resistance of Cu can be improved with the addition of ZrB2. ZrB2-Cu composites with high Cu volume fraction was successfully prepared by spark plasma sintering (SPS) process in this paper. The microstructure and properties of the sintered samples were characterized. The effect of the sintering temperature and the ZrB2 content in composites on the relative density and properties of the composites were investigated. The results show that the relative density and mechanical properties increase with the sintering temperature increasing. The optimum sintering temperature is 900 °C for 10wt.% ZrB2-Cu, 1000 °C for 20wt.% ZrB2-Cu and 1050 °C for 30wt.% ZrB2-Cu. With the ZrB2 content in composites increasing from 10wt.% to 30 wt.%, the electrical resistivity increases from 2.25×10-6 Ω.cm to 8.82×10-6 Ω.cm, the flexural strength decreases from to 539.1 MPa to 482.2 MPa and the fracture toughness decreases from to 15 MPa.m 1/2 to 9 MPa.m 1/2. The hardness (HV) of ZrB2-Cu composites is significantly enhanced by the ZrB2 particulate reinforcement, increasing from 1410 MPa for 10 wt.% ZrB2 to 2480 MPa for 30wt.% ZrB2.

Preparation and Characterisation of Gd2Zr2O7 Ceramic by Spark Plasma Sintering

2007 ◽  
Vol 280-283 ◽  
pp. 1507-1510 ◽  
Author(s):  
Qiang Xu ◽  
Wei Pan ◽  
Jing Dong Wang ◽  
Long Hao Qi ◽  
He Zhuo Miao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Microstructural Characterization ◽  
Laser Flash ◽  
Flash Method ◽  
Immersion Medium ◽  
Air Atmosphere ◽  
Plasma Sintering ◽  
Spark Plasma

Rare earth Gd2Zr2O7 ceramic was prepared by spark plasma sintering from Gd2O3 and ZrO2 powders. The powders were sintered at 1400°C for 10min. The synthesized ceramic was annealed at 800°C for 2h under air atmosphere. XRD structural and SEM microstructural characterization showed the formation of a single phase material with pyrochlore crystal structure. The relative density of Gd2Zr2O7 ceramic was measured by the Archimedes method with an immersion medium of water and the results revealed that the relative density of the ceramic was 92%. The thermal conductivity of the ceramic was tested by laser flash method from room temperature to 700°C. The result shows the thermal conductivity of Gd2Zr2O7 ceramic is lower than that of 7YSZ.

Reactive Spark Plasma Sintering of B-C-Ti-N Powders

2014 ◽  
Vol 604 ◽  
pp. 165-168
Author(s):  
Janis Grabis ◽  
Ints Steins ◽  
Aloizijs Patmalnieks ◽  
Inta Sipola
Keyword(s):  
Phase Composition ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Carbon Nanoparticles ◽  
Molar Ratio ◽  
Amorphous Boron ◽  
Reactive Sintering ◽  
Plasma Sintering ◽  
Spark Plasma

The TiB2-TiN0.1 C0.9 and B4C-TiB2 composites with relative density of 95.7-98.6% were manufactured by SPS reactive sintering mixtures of amorphous boron with TiN or TiNC and carbon nanoparticles at 1700 °C and pressure of 30 MPa during 10 min. The phase composition of the materials was determined in dependence on molar ratio of Ti/B and B/C.

Synthesis, Microstructure and Mechanical Properties of ZrB2 Ceramic Prepared by Mechanical Alloying and Spark Plasma Sintering

2010 ◽  
Vol 434-435 ◽  
pp. 165-168 ◽  
Author(s):  
Chun Feng Hu ◽  
Yoshio Sakka ◽  
Tetsuo Uchikoshi ◽  
Tohru Suzuki ◽  
Byung Koog Jang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Mechanical Alloying ◽  
Relative Density ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Heating Rates ◽  
Plasma Sintering ◽  
Spark Plasma

Dense bulk ZrB2 ceramic was synthesized by mechanical alloying (MA) and followed spark plasma sintering (SPS) using zirconium and boron as initial materials. It was found that MA process was effective to fragment the coarse metal zirconium particles from 45 m to less than 1 m within 20 hours. In comparison with the commercial ZrB2 powder, the as-obtained zirconium and boron mixture powders showed higher sinterability. When the sintering was carried out at 1800oC, the relative density of synthesized ZrB2 samples using mixture powder was above 95%, higher than that of ZrB2 sample prepared using commercial powder (73%). Vickers hardness of those ZrB2 samples was at the same level of 15 GPa. However, the fracture toughness of ZrB2 samples seemed to depend on the heating rate of the SPS process. Corresponding to the heating rates of 10, 50, and 100oC/min, the fracture toughness of as-prepared ZrB2 samples were 3.83, 3.19, and 2.74 MPa•m1/2, respectively.

Microstructure and Mechanical Properties of TiB-Ti/Ti-6Al-4V Composites Fabricated by Spark Plasma Sintering

2015 ◽  
Vol 782 ◽  
pp. 107-112
Author(s):  
Li Fen Wang ◽  
Zhao Hui Zhang ◽  
Tie Jian Su ◽  
Fu Chi Wang
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Fracture Strength ◽  
Sintering Temperature ◽  
Composite Layer ◽  
Micro Hardness ◽  
Plasma Sintering ◽  
Spark Plasma

TiB-Ti/Ti-6Al-4V composites were fabricated by spark plasma sintering (SPS) technique under a pressure of 50MPa, with sintering temperature of 1300 °C and heating rate of 100 °C /min. The effect of the TiB content in TiB-Ti composite layer on microstructures and mechanical properties of the TiB-Ti/Ti-6Al-4V composites were investigated. The results indicate that as an advanced welding method, SPS technique provided the excellent welding combination of TiB-Ti and Ti-6Al-4V. The relatively excellent mechanical properties of the joints, including the relative density of 98.6%, micro-hardness of 10.2GPa, fracture strength of 177MPa were achieved as TiB content in TiB-Ti composite layer reaches 50%.

Preparation of Fine-Grained CeO2–SiC Ceramics for Inert Fuel Matrices by Spark Plasma Sintering

2020 ◽  
Vol 56 (12) ◽  
pp. 1307-1313
Author(s):  
L. S. Alekseeva ◽  
A. V. Nokhrin ◽  
M. S. Boldin ◽  
E. A. Lantsev ◽  
A. I. Orlova ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Fine Grained ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

Densification and Thermal Conductivity of Y2O3-Doped AlN Ceramics by Spark Plasma Sintering

2007 ◽  
Vol 352 ◽  
pp. 227-231 ◽  
Author(s):  
Qiang Shen ◽  
Z.D. Wei ◽  
Mei Juan Li ◽  
Lian Meng Zhang
Keyword(s):  
Thermal Conductivity ◽  
Grain Boundaries ◽  
Spark Plasma Sintering ◽  
Particle Surface ◽  
Boundary Phase ◽  
Homogeneous Microstructure ◽  
Densification Mechanism ◽  
Sintering Additive ◽  
Plasma Sintering ◽  
Spark Plasma

AlN ceramics doped with yttrium oxide (Y2O3) as the sintering additive were prepared via the spark plasma sintering (SPS) technique. The sintering behaviors and densification mechanism were mainly investigated. The results showed that Y2O3 addition could promote the AlN densification. Y2O3-doped AlN samples could be densified at low temperatures of 1600-1700oC in 20-25 minutes. The AlN samples were characterized with homogeneous microstructure. The Y-Al-O compounds were created on the grain boundaries due to the reactions between Y2O3 and Al2O3 on AlN particle surface. With increasing the sintering temperature, AlN grains grew up, and the location of grain boundaries as well as the phase compositions changed. The Y/Al ratio in the aluminates increased, from Y3Al5O12 to YAlO3 and to Y4Al2O9. High-density, the growth of AlN grains and the homogenous dispersion of boundary phase were helpful to improve the thermal conductivity of AlN ceramics. The thermal conductivity of 122Wm-1K-1 for the 4.0 mass%Y2O3-doped AlN sample was reached.

scholarly journals Comparison of Conventional and Flash Spark Plasma Sintering of Cu–Cr Pseudo-Alloys: Kinetics, Structure, Properties

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 141
Author(s):  
Kirill V. Kuskov ◽  
Mohammad Abedi ◽  
Dmitry O. Moskovskikh ◽  
Illia Serhiienko ◽  
Alexander S. Mukasyan
Keyword(s):  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Electric Circuits ◽  
Nanostructured Particles ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Media ◽  
Copper Chromium ◽  
Kinetics Of ◽  
Structure Properties

Spark plasma sintering (SPS) is widely used for the consolidation of different materials. Copper-based pseudo alloys have found a variety of applications including as electrodes in vacuum interrupters of high-voltage electric circuits. How does the kinetics of SPS consolidation for such alloys depend on the heating rate? Do SPS kinetics depend on the microstructure of the media to be sintered? These questions were addressed by the investigation of SPS kinetics in the heating rate range of 0.1 to 50 K/s. The latter conditions were achieved through flash spark plasma sintering (FSPS). We also compared the sintering kinetics for the conventional copper–chromium mixture and for the mechanically induced copper/chromium nanostructured particles. It was shown that, under FSPS conditions, the observed maximum consolidation rates were 20–30 times higher than that for conventional SPS with a heating rate of 100 K/min. Under the investigated conditions, the sintering rate for mechanically induced composite Cu/Cr particles was 2–4 times higher compared to the conventional Cu + Cr mixtures. The apparent sintering activation energy for the Cu/Cr powder was twice less than that for Cu–Cr mixture. It was concluded that the FSPS of nanostructured powders is an efficient approach for the fabrication of pseudo-alloys.

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