SINTERING BEHAVIOR OF METALLIC AND CERAMIC POWDERS DURING PULSED ELECTRIC-CURRENT SINTERING PROCESS

An optimum route to synthesize Al2O3-based composite powders with a homogeneous dispersion of carbon nanotubes (CNTs) was investigated. CNT/Metal/Al2O3 nanocomposite powders were fabricated by thermal chemical vapor deposition (CVD) over a metal catalyst homogeneously dispersed into an Al2O3 matrix by the means of chemical and selective reduction processes. The nanocomposite powders were densified by Pulse Electric Current Sintering (PECS). The experimental results show that the CNT/Metal/Al2O3 nanocomposites have unique electrical properties.

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Densification and Grain Growth of Large-Sized Polycrystalline Al2O3 during a Two-Step Pulsed Electric Current Sintering Process

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.m2018055 ◽

2018 ◽

Vol 59 (10) ◽

pp. 1610-1615

Author(s):

Hien H. Nguyen ◽

Makoto Nanko

Keyword(s):

Electric Current ◽

Grain Growth ◽

Sintering Process ◽

Pulsed Electric Current

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Effect of two-step heating on transparency of MgAl2O4 ceramics fabricated by pulsed electric current sintering process

Journal of Science and Technology of Metal ◽

10.52923/vmfs.jstm.42021.95.02 ◽

2021 ◽

Vol 95 ◽

pp. 11-17

Author(s):

Khanh Dang Quoc ◽

◽

Yen Nguyen Ngoc ◽

Tu Dao Anh ◽

Thang Le Hong ◽

...

Keyword(s):

Grain Size ◽

Electric Current ◽

Ceramic Powder ◽

Second Step ◽

Transparent Ceramics ◽

Sintering Process ◽

Ceramic Samples ◽

Pulsed Electric Current ◽

Step Heating ◽

One Step

In this work, MgAl2O4 transparent ceramics was fabricated from combustion-synthesized nanopowders by pulsed electric current sintering (PECS) combined with two-step sintering. Ceramic powder was densitified using two-step heating, namely the first-step temperature was 1100 oC with holding time of 60 min and the second-step temperatures in range from 1300 oC to 1450 oC with 20 min duration. The results showed that the transparent ceramic samples sintered at 1100 oC/60 min – 1400 oC/20 min had grain size of 177 ± 8 nm, relative density about 99 %, transmittance up to 80 %, and Vickers hardness of 18 GPa. These values were higher than that of samples obtained by one-step sintering at 1400 oC.

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The Synthesis and Characteristics of Homogenously Dispersed CNT-Al2O3 Nanocomposites by the Thermal CVD Method and Pulsed Electric Current Sintering Process

Solid State Phenomena - Nanoscience and Technology ◽

10.4028/3-908451-30-2.295 ◽

2007 ◽

pp. 295-298

Author(s):

S.H. Yoo ◽

J.K. Yang ◽

Sung Tag Oh ◽

Kae Myung Kang ◽

Sung Goon Kang ◽

...

Keyword(s):

Electric Current ◽

Sintering Process ◽

Thermal Cvd ◽

Cvd Method ◽

Pulsed Electric Current

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In Situ Observations of Sintering Process during Pulsed Current Sintering of Al2O3, ZnO and WC Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.541 ◽

2007 ◽

Vol 534-536 ◽

pp. 541-544 ◽

Cited By ~ 1

Author(s):

Yuji Kawakami ◽

Fujio Tamai ◽

Takashi Enjoji ◽

Noboru Shikatani ◽

Tatsuya Misawa ◽

...

Keyword(s):

Electric Current ◽

Raw Materials ◽

Sintering Behavior ◽

Pulsed Current ◽

Sintering Process ◽

Electric Resistance ◽

Graphite Mold ◽

Good Conductor ◽

Zno Powder

Pulsed Current Sintering (PCS) process possesses some problems that need to be resolved. We, therefore aims at understanding phenomena of PCS process by presenting some basic data on in situ sintering behavior of PCS. In order to observe in situ sintering behavior of PCS, a special graphite mold equipped with thermo couple and electrodes were designed to measure the temperature, electric current and voltage inside the powder during PCS process. We apply three types of raw materials, especially for ZnO (thermoelectric material) as semiconductor, Al2O3 as non-conductor and WC (Tungsten Carbide) as good conductor. The observation succeeded and some valuable data were obtained. The results showed that the temperature in the Al2O3 powder is 100 K higher than the graphite mold at the temperature of 1473K and ZnO powder is 150 K higher than the graphite mold at the temperature of 1373K. The electric current and voltage were measured for each powder during PCS process. In addition, their electric resistance properties were calculated. The electric resistance showed different behavior.

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