scholarly journals Effects of Additives on Thermal Conductivity and Electrical Resistivity of SiC Ceramics by Pressureless Sintering

1988 ◽  
Vol 96 (1109) ◽  
pp. 102-105 ◽  
Author(s):  
Yukio TAKEDA ◽  
Satoru OGIHARA ◽  
Kunihiro MAEDA
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Pressureless Sintering ◽  
Sic Ceramics

scholarly journals Effect of Sintering Temperature on the Properties of Highly Electrical Resistive SiC Ceramics as a Function of Y2O3-Er2O3 Additions

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4768
Author(s):  
Sheng Ge ◽  
Xiumin Yao ◽  
Yingying Liu ◽  
Hang Duan ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Electrical Resistivity ◽  
Sintering Temperature ◽  
Secondary Phase ◽  
Sintering Additive ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

Silicon carbide (SiC) ceramics with Y2O3-Er2O3 as sintering additives were prepared by spark plasma sintering (SPS). The effects of sintering temperatures and Y2O3-Er2O3 contents on the microstructure, thermal conductivity, electrical, and mechanical properties were investigated. The increasing of sintering temperatures promoted the densification of SiC ceramics, thus increasing the thermal conductivity and electrical resistivity. With the increase of the sintering additive contents, the electrical resistivity increased due to the formation of the electrical insulating network; and the thermal conductivity first increased and then decreased, which was related to the content and distribution of the secondary phase among the SiC grains. The SiC ceramics sintered at 2000 °C with 9 wt.% Y2O3-Er2O3 exhibited higher electrical resistivity and thermal conductivity, which were 4.28 × 109 Ω·cm and 96.68 W/m·K, respectively.

scholarly journals Effects of Additives on Thermal Conductivity and Electrical Resistivity of SiC Ceramics

1987 ◽  
Vol 95 (1105) ◽  
pp. 860-863 ◽  
Author(s):  
Yukio TAKEDA ◽  
Kousuke NAKAMURA ◽  
Kunihiro MAEDA ◽  
Yasuo MATUSHITA
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Sic Ceramics

Microstructures in Pressureless Sintered AIN-SiC Ceramics

2001 ◽  
Vol 7 (S2) ◽  
pp. 1124-1125
Author(s):  
Y.D. Yu ◽  
I.-L. Tangen ◽  
M.-A. Einarsrud ◽  
R. Høier ◽  
T. Grande ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Integrated Circuits ◽  
Composite Ceramic ◽  
Substrate Material ◽  
Pressureless Sintering ◽  
Composite Ceramics ◽  
Metal Production ◽  
Sintering Additive ◽  
Sic Ceramics

Aluminum nitride (AlN) is known to have a high thermal conductivity and is one of the valid candidates as substrate material for integrated circuits. The material also has a potential in metal production and handling. However, AlN has only a moderate flexural strength and fracture toughness. It has been reported that SiCA1N composites (SiC/AIN ratio ≥ 50%) can be manufactured by means of pressureless sintering. Furthermore, it is possible to fabricate self-reinforced SiC-based materials with whisker-like crystals in composite ceramics by choosing appropriate sintering additive and condition. in the present study, we investigated the possibility to prepare in-situ formed SiC-whisker reinforced AlN-materials and studied the microstructure of the composite.An AlN-SiC composite ceramic sample (20 vol% SiC) was prepared for the investigation. The AlN-SiC composite was processed from a mixture of the starting powders with 2.5 wt% Al2O3-Y2O3 as a sintering additive.

High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

2019 ◽  
Vol 12 (03) ◽  
pp. 1950032 ◽  
Author(s):  
Yuchen Deng ◽  
Yaming Zhang ◽  
Nanlong Zhang ◽  
Qiang Zhi ◽  
Bo Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Grain Size ◽  
Phase Composition ◽  
Room Temperature ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Growth Substrate ◽  
Sic Ceramics ◽  
Evolution Of Microstructure

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

scholarly journals Improvement of mechanical properties of HfB2-based composites by incorporating in situ SiC reinforcement through pressureless sintering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Ghadami ◽  
E. Taheri-Nassaj ◽  
H. R. Baharvandi ◽  
F. Ghadami
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Relative Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Vacuum Atmosphere ◽  
Sic Reinforcement ◽  
Microstructural Studies ◽  
Composite Samples

AbstractHfB2, Si, and activated carbon powders were selected to fabricate 0–30 vol% SiC reinforced HfB2-based composite. Pressureless sintering process was performed at 2050 °C for 4 h under a vacuum atmosphere. Microstructural studies revealed that in situ SiC reinforcement was formed and distributed in the composite according to the following reaction: Si + C = SiC. A maximum relative density of 98% was measured for the 20 vol% SiC containing HfB2 composite. Mechanical investigations showed that the hardness and the fracture toughness of these composites were increased and reached up to 21.2 GPa for HfB2-30 vol% SiC and 4.9 MPa.m1/2 for HfB2-20 vol% SiC, respectively. Results showed that alpha-SiC reinforcements were created jagged, irregular, and elongated in shape which were in situ formed between HfB2 grains and filled the porosities. Formation of alpha-SiC contributed to improving the relative density and mechanical properties of the composite samples. By increasing SiC content, an enhanced trend of thermal conductivity was observed as well as a reduced trend for electrical conductivity.

Effects of Nb doping on thermoelectric properties of Zn4Sb3 at high temperatures

2009 ◽  
Vol 24 (2) ◽  
pp. 430-435 ◽  
Author(s):  
D. Li ◽  
H.H. Hng ◽  
J. Ma ◽  
X.Y. Qin
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Thermoelectric Performance ◽  
Temperature Range ◽  
A Value ◽  
Nb Doping ◽  
Thermal Conductivities

The thermoelectric properties of Nb-doped Zn4Sb3 compounds, (Zn1–xNbx)4Sb3 (x = 0, 0.005, and 0.01), were investigated at temperatures ranging from 300 to 685 K. The results showed that by substituting Zn with Nb, the thermal conductivities of all the Nb-doped compounds were lower than that of the pristine β-Zn4Sb3. Among the compounds studied, the lightly substituted (Zn0.995Nb0.005)4Sb3 compound exhibited the best thermoelectric performance due to the improvement in both its electrical resistivity and thermal conductivity. Its figure of merit, ZT, was greater than the undoped Zn4Sb3 compound for the temperature range investigated. In particular, the ZT of (Zn0.995Nb0.005)4Sb3 reached a value of 1.1 at 680 K, which was 69% greater than that of the undoped Zn4Sb3 obtained in this study.

Electrical resistivity, thermopower, and thermal conductivity of single grained (Y, Tb, Ho, Er)-Mg-Zn icosahedral quasicrystals

2000 ◽  
Vol 294-296 ◽  
pp. 715-718 ◽  
Author(s):  
K Giannò ◽  
A.V Sologubenko ◽  
M.A Chernikov ◽  
H.R Ott ◽  
I.R Fisher ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Icosahedral Quasicrystals
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