Nanostructured State-of-the-Art Thermoelectric Materials Prepared by Straight-Forward Arc-Melting Method

ABSTRACTA new version of a segmented thermoelectric unicouple incorporating advanced thermoelectric materials with superior thermoelectric figures of merit has been recently proposed and is currently under development at the Jet Propulsion Laboratory (JPL). This advanced segmented thermoelectric unicouple includes a combination of state-of-the-art thermoelectric materials based on Bi2Te3 and novel materials developed at JPL. The segmented unicouple currently being developed is expected to operate between 300 and about 975K with a projected thermal to electrical efficiency of up to 15%. The segmentation can be adjusted to accommodate various hot-side temperatures depending on the specific application envisioned. Techniques and materials have been developed to bond the different thermoelectric segments together for the nand p-legs and low contact resistance bonds have been achieved. In order to experimentally determine the thermal to electrical efficiency of the unicouple, metallic interconnects must be developed for the hot side of the thermocouple to connect the n- and p-legs electrically. The latest results in the development of these interconnects are described in this paper. Efforts are also focusing on the fabrication of a unicouple specifically designed for thermal and electrical testing.

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Effect of SiC Additions on Microstructure Evolution and Mechanical Properties of W-Based Composite Prepared by Arc-Melting

Materials Science Forum ◽

10.4028/www.scientific.net/msf.944.531 ◽

2019 ◽

Vol 944 ◽

pp. 531-536

Author(s):

Ke Jia Kang ◽

Peng Fan ◽

Jian Zhang ◽

Qiang Guo Luo ◽

Qiang Shen ◽

...

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Flexural Strength ◽

Microstructure Evolution ◽

Small Angle ◽

The Self ◽

Melting Method ◽

Arc Melting ◽

Multi Phase ◽

Strength And Ductility

In this study, the W-Si-C multi-phase composites were fabricated by an arc melting method. With addition of SiC, the grain size of W is obviously reduced, and the small angle misorientation becomes dominate, which is beneficial for the improvement of deformability. The effects of SiC additions (from 0.5 to 3wt%) on the microstructure and mechanical properties are mainly investigated. With 1 wt% SiC addition, the flexural strength reaches the highest value. The self-generation of W5Si3 may enhance the strength and ductility, but too much W5Si3 exists as brittle BP (Brittle to Plastic) microstructure. The highest flexural strength is obtained at approximately 1 vol% W5Si3.

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Synthesis, Microstructure and Crystal Structure of Perovskite-Type CeMO3 (M=Al, Ga) by Arc-Melting Method with Horizontal-Traveling Hearth

Journal of the Ceramic Society of Japan ◽

10.2109/jcersj.106.509 ◽

1998 ◽

Vol 106 (1233) ◽

pp. 509-513 ◽

Cited By ~ 2

Author(s):

Toetsu SHISHIDO ◽

Yutong THENG ◽

Akihiro SAITO ◽

Hiroyuki HOIUCHI ◽

Toshitsugu TAKAHASHI ◽

...

Keyword(s):

Crystal Structure ◽

Melting Method ◽

Arc Melting ◽

Perovskite Type

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Study on Homogenization Time and Cooling Rate on Microstructure and Hardness of Ni-42.5wt%Ti-3wt%Cu Alloy

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.297-301.489 ◽

2010 ◽

Vol 297-301 ◽

pp. 489-494 ◽

Cited By ~ 3

Author(s):

A. Etaati ◽

Ali Shokuhfar ◽

E. Omrani ◽

P. Movahed ◽

H. Bolvardi ◽

...

Keyword(s):

Cooling Rate ◽

Hardness Test ◽

Vacuum Arc ◽

Melting Method ◽

X Ray ◽

Cu Alloy ◽

Arc Melting ◽

Vacuum Arc Melting ◽

Homogenization Time ◽

Cooling Media

Over the last decades, numerous investigations have been conducted on Nitinol properties. However, the effects of alloying elements on Ni-rich NiTi alloys have been considered less. In this research, different effects of homogenization time and cooling rate on the behaviors of Ni-42.5wt%Ti-3wt%Cu alloy were evaluated. The mentioned alloy was fabricated by vacuum arc melting method. Three different homogenization times (half, one and two hours) and three cooling media (water, air and furnace) were selected. The microstructure and hardness were examined by means of optical and scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) analysis and hardness test, respectively. According to the microscopic investigations, no significant changes were observed after half an hour. However, results indicate that increasing time of homogenization leads to finer precipitations and a uniform distribution of them. The various cooling environments result in the formation of two types of precipitation phases. It was seen that in the high cooling rate, the majority of precipitations consisted of Ti2(Ni,Cu) while by decreasing cooling rate NiTiCu precipitates appeared too, which affect the hardness.

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Crystal structure and Mössbauer study of FeAl2O4

Nukleonika ◽

10.1515/nuka-2015-0012 ◽

2015 ◽

Vol 60 (1) ◽

pp. 47-49 ◽

Cited By ~ 21

Author(s):

Ilona Jastrzębska ◽

Jacek Szczerba ◽

Paweł Stoch ◽

Artur Błachowski ◽

Krzysztof Ruebenbauer ◽

...

Keyword(s):

Crystal Structure ◽

Spinel Structure ◽

Approximate Formula ◽

Argon Atmosphere ◽

Mossbauer Effect ◽

Mössbauer Study ◽

Melting Method ◽

X Ray ◽

Octahedral Sites ◽

Arc Melting

Abstract In this work the synthesis of hercynite from Fe2O3 and Al2O3 powders was carried out by arc-melting method under the protective argon atmosphere. The obtained material was characterized with the use of powder X-ray diffractometry (XRD) and Mössbauer spectroscopy (MS). A Mössbauer effect in hercynite obtained by the arc-melting method indicated the cations distribution in the spinel structure among the tetrahedral and octahedral interstices. The presence of Fe2+ ions was detected in both tetrahedral and octahedral sites while Fe3+ ions occupied only the octahedral interstices. The approximate formula of the obtained iron-aluminate spinel was as follows (Fe2+0.77Al3+0.23) (Fe3+0.07Fe2+0.05Al0.88)2O4.

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