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.

Fabrication of MgO/Graphene Composites by Combustion Synthesis and Spark Plasma Sintering

2018 ◽  
Vol 281 ◽  
pp. 125-130
Author(s):  
Nan Lu ◽  
Jia Xi Liu ◽  
Gang He ◽  
Jiang Tao Li
Keyword(s):  
Mechanical Properties ◽  
Combustion Synthesis ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
Combustion Reaction ◽  
Sintering Additive ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma

MgO/Graphene ceramic composites were fabricated by combining combustion synthesis with spark plasma sintering. MgO/Graphene mixture powders were prepared by the combustion reaction between Mg powders and CO2 gas. Dense MgO/Graphene composites were fabricated by spark plasma sintering (SPS) using LiF as the sintering additive. The effect of the sintering temperature on microstructure and mechanical properties of the prepared MgO/Graphene ceramics was discussed. The sintering temperature of the MgO/Graphene mixture powders increased from 900°C to 1300°C. The highest density of 3.43g/cm3 and hardness of 2133MPa were obtained at 1100°C. Compared with monolithic MgO ceramics, the hardness of MgO/Graphene ceramics at the same sintering temperature was increased from 840MPa to 2133MPa.

Microstructure and Properties of Spark Plasma Sintering AlN/BN Ceramics

2006 ◽  
Vol 313 ◽  
pp. 105-108 ◽  
Author(s):  
Lian Meng Zhang ◽  
Mei Juan Li ◽  
Qiang Shen ◽  
T. Li ◽  
M.Q. Yu
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Mechanical Strength ◽  
Spark Plasma Sintering ◽  
Volume Fraction ◽  
Sintering Temperature ◽  
Composite Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Full Densification

Aluminum nitride-boron nitride (AlN/BN) composite ceramics were prepared by spark plasma sintering (SPS). The sintering behaviors of AlN/BN composites with 5~15% volume fraction of BN were studied. The influences of BN content, as well as the sintering temperature on the density, microstructure, mechanical strength, thermal conductivity and machinability of the composites were also investigated. The results showed that the full densification of AlN/BN composite ceramics could be realized by SPS technique at the temperature no higher than 1800°C for 3 minutes. The thermal conductivity of AlN/BN composites is in the range of 66~79W/mK, and AlN/BN composites can be cut or drilled by carbides or even steel tools when BN content is 15% volume fraction. The mechanical strength of AlN/BN composites is about 330MPa and is not remarkably affected by the addition of BN. The improvement of mechanical properties of AlN/BN composite ceramics is due to the fine and homogenous microstructure developed in the SPS process.

Fabrication and Thermoelectric Properties of N-Type Bi2Te3 Based Compounds by Spark Plasma Sintering

2005 ◽  
Vol 486-487 ◽  
pp. 253-256 ◽  
Author(s):  
D.M. Lee ◽  
Cheol Ho Lim ◽  
Dong Choul Cho ◽  
Seung Y. Shin ◽  
Won Seung Cho
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Powder Size ◽  
Plasma Sintering ◽  
Spark Plasma

N-type Bi2Te3 based thermoelectric compound was prepared by spark plasma sintering with a temperature range of 340~460°C and powder size of ~75㎛, 76~150㎛, 151~250㎛. Thermoelectric properties of the compound were measured as a function of the sintering temperature and powder size. With increasing sintering temperature, the electrical resistivity and thermal conductivity of the compound greatly changed because of the increase in relative density. The Seebeck coefficient and electrical resistivity were varied largely with increasing powder size. Therefore, the compound sintered at 460°C, with the powder of ~75㎛, showed a figure of merit of 2.44 x 10-3/K. Also, the bending strength was 75MPa.

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.

Effects of Al, B and C Additives on Microstructure and Mechanical Properties of Spark-Plasma-Sintered SiC Ceramics

2005 ◽  
Vol 287 ◽  
pp. 329-334 ◽  
Author(s):  
Kyeong Sik Cho ◽  
Kwang Soon Lee
Keyword(s):  
Mechanical Properties ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Applied Pressure ◽  
Fast Heating ◽  
Soaking Time ◽  
Sic Ceramics ◽  
Prolonged Annealing ◽  
Plasma Sintering ◽  
Spark Plasma

Densification of the SiC powder without and with additives B+C or Al+B+C was carried out by spark plasma sintering (SPS). The unique features of the process are the possibilities of using a very fast heating rate and a short holding time to obtain fully dense materials. The heating rate and applied pressure were kept at 100°C/ min and 40 MPa, while the sintering temperature and soaking time varied from 1650-1850°C for 10-40 min, respectively. The SPS-sintered specimens with the addition of B+C or Al+B+C at 1850°C reached near-theoretical density. The 3C major crystalline phase of SiC was transformed to 6H at 1800°C and translated to 4H during prolonged annealing at 1850°C. The strength of 531.0 MPa and the fracture toughness of 3.9 MPa·m1/2 were obtained by the addition of Al+B+C to SiC prepared at 1850°C for 10 min.

Microstructure and Thermoelectric Properties of P-Type Bi0.5Sb1.5Te3 Compounds Prepared by Spark Plasma Sintering

2006 ◽  
Vol 510-511 ◽  
pp. 1122-1125
Author(s):  
Won Seung Cho ◽  
Dong Choul Cho ◽  
Cheol Ho Lim ◽  
C.H. Lee ◽  
Woon Suk Hwang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Hydrogen Reduction ◽  
Sintering Temperature ◽  
Reduction Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

The microstructure and thermoelectrical properties of the 4wt% Te doped p-type Bi0.5Sb1.5Te3 compounds, fabricated by using spark plasma sintering in the temperature ranging from 250°C to 350°C, were characterized. The density of the sintered compounds was increased to 99.2% of theoretical density by carrying out the consolidation at 350oC for 2 min. The Seebeck coefficient, thermal conductivity and electrical resistivity were dependent on hydrogen reduction process and sintering temperature. The Seebeck coefficient increased with reduction process while the electrical resisitivity significantly decreased. Also, the electrical resistivity decreased and thermal conductivity increased with sintering temperature. The results suggest that the carrier density and mobility vary with reduction process and sintering temperature. The highest figure of merit of 3.5×10-3/K was obtained for the compounds spark plasma sintered at 350°C for 2 min by using the hydrogen-reduced powders.

Synthesis and Thermoelectric Properties of N-Type Bi2Te2.7Se0.3 Compounds by Spark Plasma Sintering

2005 ◽  
Vol 486-487 ◽  
pp. 654-657
Author(s):  
Dong Choul Cho ◽  
Cheol Ho Lim ◽  
Ki Tae Kim ◽  
Seung Y. Shin ◽  
D.M. Lee ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Hydrogen Reduction ◽  
Sintering Temperature ◽  
Reduction Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Temperature Time

Thermoelectric properties of the spark plasma sintered n-type Bi2Te2.7Se0.3 compounds were characterized with the sintering temperature, time and hydrogen reduction process. The Seebeck coefficient, electrical resistivity and thermal conductivity were dependent on hydrogen reduction process as well as sintering temperature. The Seebeck coefficient and electrical resistivity decreased and thermal conductivity increased with reduction treatment and sintering temperature. The results suggest that the carrier density varies with the dissolved oxygen and Te vacancies generated during the pulverization process. The highest figure of merit of 3.11×10-3/K was obtained for the compounds spark plasma sintered at 460°C for 16min by using the reduced powders.

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.

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