scholarly journals Thermoelectric Properties of Nano/microstructured p-Type Bi0.4Sb1.6Te3 Powders Fabricated by Mechanical Alloying and Vacuum Hot Pressing

2013 ◽  
Vol 43 (6) ◽  
pp. 1718-1725 ◽  
Author(s):  
Pee-Yew Lee ◽  
Joey Hao ◽  
Tz-Yuan Chao ◽  
Jing-Yi Huang ◽  
Huey-Lin Hsieh ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Vacuum Hot Pressing ◽  
P Type

Synthesis and Thermoelectric Properties of Undoped Half-Heusler Zr-Co-Sb Alloy Processed by Mechanically Alloying and Hot Pressing

2011 ◽  
Vol 695 ◽  
pp. 69-72
Author(s):  
Il Ho Kim ◽  
Joon Chul Kwon ◽  
Young Geun Lee ◽  
Sung Lim Ryu ◽  
Man Soon Yoon ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Hot Pressing ◽  
Heusler Alloys ◽  
Processing Route ◽  
Mechanically Alloyed ◽  
Fundamental Study ◽  
Vacuum Hot Pressing ◽  
Fine Grain

Half-Heusler alloys are one of the potential thermoelectric materials for medium to high temperature range application. As a part of fundamental study to establish processing route and to observe thermoelectric properties in undoped state, ZrCoSb was selected, processed and evaluated. In an attempt to produce a half-Heusler thermoelectric materials having ultra fine grain structures, ZrCoSb was synthesized by mechanical alloying of stoichiometric elemental powder compositions, and consolidated by vacuum hot pressing. Phase transformations during mechanical alloying and hot consolidation were investigated using XRD, SEM and EDS. Single-phase, half-Heusler was successfully produced by vacuum hot pressing using as-milled powders without subsequent annealing. Thermoelectric properties as functions of temperature were evaluated in terms of Seebeek coefficient, electrical conductivity, thermal conductivity and the figure of merit for the hot pressed specimens. Mechanically alloyed half-Heusler phase, ZrCoSb, appeared to have a great potential as a thermoelectric materials in this study.

Thermoelectric Properties of P-Type (Bi1−xSbx)2Te3 Fabricated by Mechanical Alloying Process

1997 ◽  
Vol 478 ◽  
Author(s):  
Boo Yang Jung ◽  
Jae Shik Choi ◽  
Tae Sung Oh ◽  
Dow-Bin Hyun
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Alloy Powder ◽  
Figure Of Merit ◽  
Processing Time ◽  
Pressing Temperature ◽  
Acceptor Dopant ◽  
Maximum Value ◽  
P Type

AbstractThermoelectric properties of polycrystalline (Bi1−xSbx)2Te3 (0.75 ≤ x ≤ 0.85), fabricated by mechanical alloying and hot pressing methods, have been investigated. Formation of (Bi0.25Sb0.75)2Te3 alloy powder was completed by mechanical alloying for 5 hours at ball- to-material ratio of 5: 1, and processing time for (Bi1−xSbx)2Te3 formation increased with Sb2Te3 content x. When (Bi0.25Sb0.75)2Te3 was hot pressed at temperatures ranging from 300°C to 550°C for 30 minutes, figure-of-merit increased with hot pressing temperature and maximum value of 2.8 × 10−3/K could be obtained by hot pressing at 550°C. When hot pressed at 550°C, (Bi0.2Sb0.8)2Te3 exhibited figure-of-merit of 2.92 × 10−3/K, which could be improved to 2.97 × 10−3/K with addition of 1 wt% Sb as acceptor dopant.

Thermoelectric Properties of Nanostructured CoSb3 Synthesized by Mechanical Alloying

2007 ◽  
Vol 534-536 ◽  
pp. 1425-1428
Author(s):  
Soon Chul Ur ◽  
Joon Chul Kwon ◽  
Moon Kwan Choi ◽  
Soon Young Kweon ◽  
Tae Whan Hong ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Figure Of Merit ◽  
Single Phase ◽  
Phonon Scattering ◽  
Stoichiometric Composition ◽  
Processing Route ◽  
Vacuum Hot Pressing

Undoped CoSb3 powders were synthesized by mechanical alloying of elemental powders using a nominal stoichiometric composition. Nanostructured, single-phase skutterudite CoSb3 was successfully produced by vacuum hot pressing using as-milled powders without subsequent annealing. Phase transformations during synthesis were investigated using XRD, and microstructure was observed using SEM and TEM. Thermoelectric properties in terms of Seebeck coefficient, electrical conductivity, thermal conductivity and figure of merit were systematically measured and compared with the results of analogous studies. Lattice thermal conductivity was reduced owing to increasing phonon scattering in nanostructured CoSb3, leading to enhancement in the thermoelectric figure of merit. Mechanical Alloying associated with vacuum hot pressing technique offers an alternative potential processing route for the production of skutterudites.

scholarly journals Thermoelectric Properties of Alumina-Doped Bi0.4Sb1.6Te3 Nanocomposites Prepared through Mechanical Alloying and Vacuum Hot Pressing

Energies ◽  
2015 ◽  
Vol 8 (11) ◽  
pp. 12573-12583 ◽  
Author(s):  
Chung-Kwei Lin ◽  
May-Show Chen ◽  
Rong-Tan Huang ◽  
Yu-Chun Cheng ◽  
Pee-Yew Lee
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Vacuum Hot Pressing

Mechanical Alloying and Thermoelectric Properties of CoSb3 Skutterudite

2005 ◽  
Vol 486-487 ◽  
pp. 642-645 ◽  
Author(s):  
Moon Kwan Choi ◽  
Soon Chul Ur ◽  
Joon Chul Kwon ◽  
K.W. Cho ◽  
Il Ho Kim ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Mechanical Alloying ◽  
Phase Transformations ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Single Phase ◽  
Stoichiometric Composition ◽  
Subsequent Annealing ◽  
Vacuum Hot Pressing ◽  
Temperature Dependences

In an effort to synthesize homogenized single phase d-CoSb3, this study considers the mechanical alloying (MA) of elemental Co and Sb powders using a nominal stoichiometric composition followed by hot pressing. Single phase, undoped CoSb3 skutterudites were successfully produced by vacuum hot pressing using MA powders without subsequent annealing. Phase transformations during mechanical alloying, powder annealing, and hot pressing were systematically investigated using XRD and SEM. Thermoelectric properties were measured and compared with the results of similar studies. Temperature dependences were also evaluated, and their correlations to phase transformation were examined.

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