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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Microwave synthesis of ultra-high temperature ceramic ZrC nanopowders

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Autor(es):
Yasno, Juan P. [1] ; Gunnewiek, Rodolfo F. K. [1] ; Kiminami, Ruth H. G. A. [1]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Fed Sao Carlos, Dept Mat Engn, Rod Washington Luiz, Km 235, BR-13565905 Sao Carlos, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: ADVANCED POWDER TECHNOLOGY; v. 30, n. 7, p. 1348-1355, JUL 2019.
Citações Web of Science: 0
Resumo

Ultra-high temperature ceramic zirconium carbide (ZrC) nanopowders were synthesized for the first time via a microwave-assisted carbothermal reduction reaction using zirconia (ZrO2) and carbon black (C) as the starting materials. The effect of the reaction time on the formation of ZrC nanoparticles was examined. The as-synthesized samples were characterized using X-ray diffraction (XRD), helium pycnometry, Brunauer-Emmett-Teller (BET) N-2 adsorption, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The lattice constant and interplanar distance (d(111)) were calculated, and the crystallite size was obtained using the Scherrer formula. Results from the experiment show highly crystalline ZrC, with crystallites less than 50 nm and nearly-spherical morphology, using 3 kW of power and only 50 min of reaction time, with a maximum reaction temperature of 1400 degrees C, lower than those involved using the conventional heating carbothermal reduction. The reaction time was similar to 2 h shorter than that required by using a combined sol-gel and microwave-assisted carbothermal reduction method, used to prepare submicron ZrC powders (200-300 nm). The high heating rate achieved on the synthesis was favored by the excellent microwave absorption of carbon black, and the uniform heating at molecular level induced by the microwaves on the samples. (C) 2019 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved. (AU)

Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
Beneficiário:Elson Longo da Silva
Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs