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Grain size dependent phase transition and Hall-Petch relationship in nanocrystalline Scandia-Zirconia: an in-situ TEM study

Grant number: 17/25501-3
Support type:Scholarships abroad - Research Internship - Post-doctor
Effective date (Start): March 01, 2018
Effective date (End): February 28, 2019
Field of knowledge:Engineering - Materials and Metallurgical Engineering
Principal Investigator:Eliana Navarro dos Santos Muccillo
Grantee:Robson Lopes Grosso
Supervisor abroad: Shen J Dillon
Home Institution: Instituto de Pesquisas Energéticas e Nucleares (IPEN). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São Paulo , SP, Brazil
Local de pesquisa : University of Illinois at Urbana-Champaign, United States  
Associated to the scholarship:16/06205-1 - Characterization of nanostructured scandia-zirconia ceramics consolidated by Spark Plasma Sintering, BP.PD

Abstract

Scandia-zirconia (ScZ) has a great technological interest for solid electrolyte applications due to the highest ionic conductivity among zirconia-based ceramics. However, ScZ usually requires high temperatures (> 1600 °C) to achieve 95% relative density by conventional sintering. Fully dense nanocrystalline ScZ specimens were obtained by recently proposed deformable punch spark plasma sintering technique (DP-SPS). It has been postulated that DP-SPS method inhibits grain growth due to the low processing temperatures and eliminates isolated residual pores due to high pressure application. Samples of ZrO2 containing 6 to 20 mol% Sc2O3 were synthesized by coprecipitation, calcined, and sintered by DP-SPS at low temperatures (700 to 800 °C) and high pressures (1.5 and 2 GPa). X-ray diffraction patterns only revealed a cubic single phase in polycrystalline samples with average grain size between 8 and 20 nm. In this work, grain size dependent phase transition and mechanical properties in nanostructured ScZ will be investigated by in-situ transmission electron microscopy (TEM). Phase transitions as a function of grain size will be investigated during coarsening by high temperature in-situ TEM. Mechanical properties will be determined via in-situ TEM nanomechanical testing and Hall-Petch relationship will be verified by changing grain size for a specific composition and polymorph. Sintered samples will be carefully prepared by focused ion beam. Considering that there is scarce information about microstructure of fully dense nanostructured (< 20 nm) ceramics in the current literature, results originated from this work will represent original data with relevant scientific contribution.

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)
GROSSO, ROBSON L.; MUCHE, DERECK N. F.; YONAMINE, TAEKO; MUCCILLO, ELIANA N. S.; DILLON, SHEN J.; CASTRO, RICARDO H. R. Sintering of translucent and single-phase nanostructured scandia-stabilized zirconia. Materials Letters, v. 253, p. 246-249, OCT 15 2019. Web of Science Citations: 0.

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