Deformation behavior of porous ceramics based on zirconium oxide

• Published in: AIP conference proceedings Vol. 2509; no. 1
• Main Authors: Buyakov, Ales, Kulkov, Sergey
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Melville American Institute of Physics 22.04.2022
• Subjects: Ceramics; Crystallites; Grain size; Magnesium; Microcracks; Plastic deformation; Pseudoplasticity; Sintering (powder metallurgy); Solid phases; Ultimate tensile strength; Zirconium oxides
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0084260

The study investigates the deformation behavior of a ceramic composite based on oxides of zirconium and magnesium, with a bimodal pore structure, subject to long-term isothermal sintering at a temperature of 1600°C. It was found that the crystallite size increases in the course of isothermal holding. However, at the stage of completion of the second stage of solid-phase sintering, the crystallite growth rate noticeably decreases. Ceramics sintered with an isothermal holding of up to 180 min exhibit a pseudo-plastic deformation behavior. The dependence of the ultimate strength of the studied ceramics on the grain size and crystallites has the form of a Hall–Petch-type dependence with a maximum. This maximum corresponds to a change in the nature of the deformation behavior from pseudo-plastic, accompanied by the formation of many microcracks, to brittle, in which the ceramics are destroyed during the formation of a single main crack.