Nanomechanical and microstructural properties of experimental bilayered zirconia ceramics after hydrothermal aging

Author(s):Show less -

Sousa, Edisa O. ; Campos, Tiago M. B. ; Bergamo, Edmara T. P. ; Alves, Larissa M. M. ; Benalcazar-Jalkh, Ernesto B. ; Marun, Manoela M. ; Galli, Mateus Z. ; Carvalho, Laura F. ; Thim, Gilmar Patrocinio ; Tebcherani, Sergio M. ; Witek, Lukasz ; Coelho, Paulo G. ; Piza, Mariana M. T. ; dos Santos, Claudinei ; Yamaguchi, Satoshi ; Bonfante, Estevam A.

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 50, n. 19, p. 10-pg., 2024-08-09.

Abstract

Two experimental ceramic systems, 3Y-TZP/5Y-PSZ (3Y/5Y) and 4Y-PSZ/5Y-PSZ (4Y/5Y), underwent analysis before (3Y/5Yi or 4Y/5Yi) and after hydrothermal aging (3Y/5Ya or 4Y/5Ya) to simulate low-temperature degradation (LTD). The samples were sintered and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy, alongside nanoindentation tests to measure elastic modulus (Em) and hardness (H). Assessments were conducted on the external surfaces and at individual layers on crosssectioned samples at predetermined regions of interest (ROIs). Degraded superficial regions were observed in the cross-sectional SEM images of the 3Y and 4Y zirconia layers after aging. XRD indicated a tetragonal -> monoclinic phase transformation in the aged groups for both 3Y (66 % m-ZrO2) and 4Y (29 % m-ZrO2). Raman spectroscopy revealed monoclinic phase amounts of 86 % for 3Y and 62 % for 4Y in the degradation regions observed in the SEM micrographs. Monoclinic phase peaks were virtually no longer detected in either material beyond a depth of 15 mu m. Hydrothermal aging significantly diminished the H and Em values for the 3Y and 4Y zirconia surfaces. For the analysis of different zirconia surfaces within the same subgroup, all pairwise comparisons showed statistically significant differences, except for the values of H of 3Y/5Yi and Em for 4Y/5Yi. Regarding the nanoindentation results of cross-sectioned samples, the aging protocol did not affect the H and Em values of the equivalent ROIs (layers), regardless of the bilayered system. However, significant differences in H values were observed among the ROIs (layers) within the same bilayered system. Despite surface changes, nanomechanical properties remained preserved below the surface and at the interfaces of bilayered materials after aging. Nanoscale H values varied among some layers and interfaces, whereas the Em values exhibited differences across certain surfaces. (AU)

• FAPESP's process: 21/07440-2 - Graduated glass infiltration in an ultra-translucent zirconia (5Y-PSZ): synthesis, processing and characterization of physical and mechanical properties
• Grantee: Larissa Marcia Martins Alves
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/12874-9 - Infiltration graded by glass in an experimental composite based on whiskers of alumina and zircônia: development, microstructural characterization and optical and mechanical properties
• Grantee: Tiago Moreira Bastos Campos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/05496-3 - Multi-user equipment approved in grant 21/06730-7: Macrodurômetro VH1150 - Buehler
• Grantee: Estevam Augusto Bonfante
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 21/06730-7 - Towards sustainable zirconia recycled from milling waste and boosted by glass infiltration for restorative use, and of the development of strong, graded, and aging resistant multilayered zirconia blocks
• Grantee: Estevam Augusto Bonfante
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2
• FAPESP's process: 23/07289-8 - Influence of low temperature degradation on the wear resistance of recycled translucent zirconia
• Grantee: Larissa Marcia Martins Alves
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 22/07733-2 - Physical and mechanical characterization of a bilayered zirconia system: influence of hydrothermal aging
• Grantee: Edisa de Oliveira Sousa
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 22/05495-7 - Multi-user equipment approved in grant 21/06730-7: ElectroPuls E3000 All-Electric Dynamic Test Instrument, INSTRON
• Grantee: Estevam Augusto Bonfante
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 22/07157-1 - Physical and mechanical characterization of a multilayered system using recycled zirconia
• Grantee: Ernesto Byron Benalcazar Jalkh
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 23/02142-9 - Nanomechanical characterization of an experimental bilayered zirconia system
• Grantee: Edisa de Oliveira Sousa
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree