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Instrumentation and automation of a furnace adapted to flash sintering

Grant number: 18/04331-5
Support type:Scholarships in Brazil - Doctorate (Direct)
Effective date (Start): May 01, 2018
Effective date (End): October 01, 2020
Field of knowledge:Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
Principal Investigator:Eliria Maria de Jesus Agnolon Pallone
Grantee:João Vitor Campos
Home Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
Associated scholarship(s):19/03786-1 - Instrumentation and automation of a tube furnace adapted to flash sintering, BE.EP.DD

Abstract

In the last decade the flash sintering technique (SF) was presented in the literature. This technique consists in the application of electric field in the sample concomitant with the increase of temperature of the furnace, during the sintering. Materials with negative temperature coefficient have their electrical resistance inversely proportional to temperature. Thus, at a given temperature an electric current is induced through the sample. This electric current heats the sample abruptly, causing its retraction in a few seconds, reducing the grain growth when compared to conventional sintering. In this context, the present work aims to automate, for the first time, the control of SF parameters during sample retraction, and identify the correlation between the SF parameters and the physical, mechanical and microstructural characteristics of tetragonal zirconia stabilized with 3 mol% of yttria (3Y-TZP). In the first stage of this work, the tubular furnace was adapted and tested to perform SF. Several results have already been obtained from different configurations of SF for 3Y-TZP, for example, 3Y-TZP was sintered in this furnace at 950°C under electric field of 90 V/cm reaching 97% of densification. In the second stage of the work, 3Y-TZP will be sintered under 50 different SF conditions in the adapted furnace, in order to establish a correlation between the electrical parameters of SF and the physical, mechanical and microstructural characteristics of the sintered material. In addition, experiments will be carried out where the current density will be varied during the densification of the sample, aiming the control of the microstructure. For this, a control software that allows the variation of this parameter in milliseconds is being elaborated. In this way, it is expected that the instrumentation and automation of the SF process will allow the accurate control of the structuring of the microstructure of the 3Y-TZP, thus improving its mechanical performance. (AU)

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
CAMPOS, V, JOAO; LAVAGNINI, ISABELA R.; PEREIRA DA SILVA, JOAO G.; FERREIRA, JULIETA A.; SOUSA, V, RAFAEL; MUECKE, ROBERT; GUILLON, OLIVIER; PALLONE, ELIRIA M. J. A. Flash sintering scaling-up challenges: Influence of the sample size on the microstructure and onset temperature of the flash event. SCRIPTA MATERIALIA, v. 186, p. 1-5, SEP 2020. Web of Science Citations: 0.
LAVAGNINI, ISABELA R.; CAMPOS, V, JOAO; FERREIRA, JULIETA A.; PALLONE, ELIRIA M. J. A. Microstructural evolution of 3YSZ flash-sintered with current ramp control. Journal of the American Ceramic Society, v. 103, n. 6 FEB 2020. Web of Science Citations: 0.
CAMPOS, JOAO VITOR; LAVAGNINI, ISABELA REIS; DE SOUSA, RAFAEL VIEIRA; FERREIRA, JULIETA ADRIANA; DE JESUS AGNOLON PALLONE, ELIRIA MARIA. Development of an instrumented and automated flash sintering setup for enhanced process monitoring and parameter control. Journal of the European Ceramic Society, v. 39, n. 2-3, p. 531-538, FEB-MAR 2019. Web of Science Citations: 3.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.