Optimizing Thermoelectric Properties of In Situ Plasma-Spray-Synthesized Sub-stoichiometric TiO2-x Deposits

0507465 - ÚFP 2020 RIV US eng J - Journal Article
Lee, H. - Seshadri, R. - Pala, Zdeněk - Sampath, S.
Optimizing Thermoelectric Properties of In Situ Plasma-Spray-Synthesized Sub-stoichiometric TiO2-x Deposits.
Journal of Thermal Spray Technology. Roč. 27, č. 6 (2018), s. 968-982. ISSN 1059-9630. E-ISSN 1544-1016
R&D Projects: GA ČR GB14-36566G
Institutional support: RVO:61389021
Keywords : stabilized zirconia coatings * thermal-conductivity * microstructure * phase * performance * nanofluids * metastable phases * plasma spray * thermal spray * thermoelectric properties * TiO2-x * titanium oxides
OECD category: Materials engineering
Impact factor: 2.129, year: 2018
Method of publishing: Limited access
https://link.springer.com/article/10.1007%2Fs11666-018-0731-1

In this article, an attempt has been made to relate the thermoelectric properties of thermal spray deposits of sub-stoichiometric titania to process-induced phase and microstructural variances. The TiO2-x deposits were formed through the in situ reaction of the TiO1.9 or TiO1.7 feedstock within the high-temperature plasma flame and manipulated via varying the amounts of hydrogen fed into in the thermal plasma. Changes in the flow rates of H-2 in the plasma plume greatly affected the in-flight particle behavior and composition of the deposits. For reference, a high-velocity oxy-fuel spray torch was also used to deposit the two varieties of feedstocks. Refinements to the representation of the in-flight particle characteristics derived via single particle and ensemble diagnostic methods are proposed using the group parameters (melting index and kinetic energy). The results show that depending on the value of the melting index, there is an inverse proportional relationship between electrical conductivity and Seebeck coefficient, whereas thermal conductivity has a directly proportional relationship with the electrical conductivity. Retention of the original phase and reduced decomposition is beneficial to retain the high Seebeck coefficient or the high electrical conductivity in the TiO2 system.
Permanent Link: http://hdl.handle.net/11104/0298450