Autor(es)

Campos, Tiago Moreira Bastos ; Silva, Ana Carolina da ; Spirandeli, Bruno Roberto ; Bergamo, Edmara Tatiely Pedroso ; Alves, Larissa Marcia Martins ; Jalkh, Ernesto Byron Benalcazar ; Thim, Gilmar Patrocinio ; Santos, Claudinei ; Coelho, Paulo G. ; Bonfante, Estevam Augusto

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS; v. 164, p. 12-pg., 2025-04-01.

Resumo

This study evaluated the development and characterization of alumina-toughened zirconia (ATZ) composites containing 10 wt% Al2O3 whiskers subjected to the glass infiltration. To obtain ATZ 90/10 composites, the commercial 3Y-TZP powder was mixed with synthesized alumina whiskers and subsequently compacted. Discs (n = 210) were pre-sintered at 1000 degrees C for 1 h. The infiltration of glass (68SiO2-11.7Al2O3-3CaO-7.3Na2O10K2O) was developed by mixing glass and propylene glycol, which was then applied onto ATZ pre-sintered specimens. For infiltration, the graded discs were divided into two different sintering protocols: protocol 1 (1550 degrees C for 2 h) and protocol 2 (1350 degrees C for 1 h followed by 1550 degrees C for 2 h). As a control group, non-infiltrated specimens were sintered using protocol 1. The specimens were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Hardness, fracture toughness, and biaxial flexural strength tests followed by fractographic analysis were performed. Statistical analyses were conducted using Weibull distribution to calculate the material's modulus (m) and characteristic strength (95% CI), as well as ANOVA tests. High-aspect ratio alumina whiskers (10 mu m x 200 nm) were synthesized. While the control group's XRD patterns evidenced only characteristic tetragonal zirconia and alpha-alumina peaks, the glass-infiltrated groups did not present characteristic peaks of crystalline materials. ATZ with alumina whiskers showed higher fracture toughness and characteristic strength compared to conventional ATZ. Furthermore, glass-infiltration improved the characteristic strength of conventional ATZ with no significant differences observed in the Weibull modulus. For W-G-2, C, and W groups the fractures originated at the zirconia surface, while for C-G-1-, C-G-2, and W-G-1 the origins were inside the ceramic microstructure. In conclusion, the development of ATZ with alumina whiskers increased the biaxial flexural strength and fracture toughness compared to conventional ATZ. The glass gradation significantly improved the characteristic strength of conventional ATZ regardless of the sintering protocol used, whereas it only improved the characteristic strength of whisker-reinforced ATZ when a single sintering was performed. Additionally, the sintering protocol influenced the thickness and amount of glass gradation in the composites. (AU)

• Processo FAPESP: 21/06730-7 - Rumo à zircônia sustentável reciclada a partir do descarte de usinagem e melhorada por infiltração graduada e ao desenvolvimento de blocos de zircônia multicamada resistentes, graduados, e não suscetíveis ao envelhecimento
• Beneficiário: Estevam Augusto Bonfante
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores - Fase 2
• Processo FAPESP: 22/07157-1 - Caracterização física e mecânica de um sistema multicamadas utilizando zircônia reciclada
• Beneficiário: Ernesto Byron Benalcazar Jalkh
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 21/07440-2 - Infiltração graduada por vidro em uma zircônia ultra translúcida (5Y-PSZ): síntese, processamento e caracterização das propriedades físicas e mecânicas
• Beneficiário: Larissa Marcia Martins Alves
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 20/12874-9 - Infiltração gradada por vidro em um compósito experimental à base de whiskers de alumina e zircônia: desenvolvimento, caracterização microestrutural e das propriedades ópticas e mecânicas
• Beneficiário: Tiago Moreira Bastos Campos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 21/08018-2 - Caracterização nanomecânica de compósitos ZTA e ATZ infiltrados por vidro
• Beneficiário: Edmara Tatiely Pedroso Bergamo
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 19/08693-1 - Compósitos experimentais à base de alumina e zircônia infiltrados por vidro: caracterização microestrutural e das propriedades ópticas e mecânicas.
• Beneficiário: Edmara Tatiely Pedroso Bergamo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado