Temperature effect on elastic and fracture behaviour of lead-free piezoceramic BaTiO3

0567497 - ÚFM 2024 RIV GB eng J - Journal Article
Chlup, Zdeněk - Drdlík, D. - Hadraba, Hynek - Ševeček, Oldřich - Šiška, Filip - Erhart, J. - Máca, K.
Temperature effect on elastic and fracture behaviour of lead-free piezoceramic BaTiO3.
Journal of the European Ceramic Society. Roč. 43, č. 4 (2023), s. 1509-1522. ISSN 0955-2219. E-ISSN 1873-619X
R&D Projects: GA ČR GA21-24805S
Institutional support: RVO:68081723
Keywords : Barium titanate * Fracture resistance * Curie temperature * fem * Thermal stresses
OECD category: Ceramics
Impact factor: 5.7, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0955221922009050?via%3Dihub

Ferroelectric ceramics, especially piezoceramics, are widely used in the field of sensors, micromanipulators, and capacitors. Barium titanate and its derivates are the first choices between lead-free materials. The main aim of the paper is to clarify fundamental processes taking place in the vicinity of Curie temperature with a focus on the fracture behaviour of pure polycrystalline barium titanate. The explanation of observed changes in the me-chanical behaviour of this material is based on the experimental approach supported by numerical simulations utilising features of the real microstructure on the grain level. Several model materials with various grain mi-crostructures were manufactured from the submicron barium titanate powder sintered at various temperatures. Two resulting materials with a suitable distribution of grains were selected for further investigation. The grain size influenced not only the exact position of the temperature of the Curie point but also the kinetics of the lattice transformation, elastic, and fracture properties. The significant drop observed in the fracture resistance was attributed to the development of localised internal thermal stresses, which was supported by the results of the performed numerical simulations. The coincidence of the volume change of neighbouring grains due to lattice transformation together with a significant variation in elastic properties can lead up to a 20% decrease in the measured fracture toughness. Understanding this behaviour is essential for the processing and correct application of lead-free barium titanate materials.
Permanent Link: https://hdl.handle.net/11104/0341696