Influence of flash sintering parameters on ZnO densification and microstructure

• Grant number: 18/11143-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): September 01, 2018
• Effective date (End): January 04, 2022
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Eliria Maria de Jesus Agnolon Pallone
• Grantee: Ana Gabriela Storion
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Alternative techniques to conventional sintering have been studied aiming to control microstructure and grain growth, in addition to a lower energy consumption. Among these techniques flash sintering (FS) can be highlighted. This process consists of exposing a material in direct contact with two electrodes, by which a high-intensity electric field is applied simultaneously to conventional heating until at a critical point the flash event starts, resulting in an almost instantaneous full densification. Zinc oxide (ZnO), an n-type semiconductor used in various electronic and optoelectronic devices, consists of a material susceptible to this technique. In this context, the objective of this project is to investigate the influence of the FS process parameters (furnace temperature, electric field strength, current mode, pressure, oxidizing and non-oxidizing atmosphere, and current density) in the densification and microstructure of ZnO specimen prepared with powders of micro and nanometric dimensions. The results will be compared to conventional sintering, in order to study densification and grain growth. A meticulous variation of FS parameters is essential for the understanding of the mechanisms involved in the flash event. In this context the automated furnace to be used in this project will be of fundamental importance, since it allows to control in a detailed way the studied parameters. Finally, from this study it will be possible a better understanding of FS applied to ZnO, and propose mechanisms that may explain the processes involved in FS.

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)

LAVAGNINI, ISABELA REIS; CAMPOS, JOAO VITOR; STORION, ANA GABRIELA; LOBO, ANDERSON OLIVEIRA; RAJ, RISHI; DE JESUS AGNOLON PALLONE, ELIRIA MARIA. Influence of flash sintering on phase transformation and conductivity of hydroxyapatite. CERAMICS INTERNATIONAL, v. 47, n. 7, A, p. 9125-9131, APR 1 2021. (18/04331-5, 18/11143-0, 19/03786-1)

STORION, ANA G.; LAVAGNINI, ISABELA R.; CAMPOS, V, JOAO; DA SILVA, JOAO G. P.; MAESTRELLI, SYLMA C.; PALLONE, ELIRIA M. J. A.. Effect of thermal insulation on microstructural homogeneity and onset temperature of flash sintered materials. Journal of the European Ceramic Society, v. 41, n. 15, p. 7807-7815, DEC 2021. (18/11143-0, 19/14677-9, 18/04331-5)

STORION, ANA GABRIELA; FERREIRA, JULIETA ADRIANA; MAESTRELLI, SYLMA CARVALHO; DE JESUS AGNOLON PALLONE, ELIRIA MARIA. Influence of the forming method on flash sintering of ZnO ceramics. CERAMICS INTERNATIONAL, v. 47, n. 1, p. 965-972, JAN 1 2021. (18/11143-0, 15/07319-8)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

STORION, Ana Gabriela. Influence of the flash sintering parameters on the densification and microstructure of ZnO. 2023. Doctoral Thesis - Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT) Pirassununga.