resumo
In this study, zirconia-based ceramics doped with different yttria contents (3, 4 or 5 mol.%) were processed by a material extrusion additive manufacturing technique, Direct Ink Writing (DIW). A gel-based approach, using polyethylene glycol (PEG), Laponite (R) nano-clay and Dibutyl Phthalate (DBP), was used for the development of ceramic inks with solid load approximate to 31 vol% and suitable rheological properties to be processed by DIW. Prismatic and cylindric samples were printed (crossed layers at 90 degrees; print speed = 10 mm/s; nozzle o = 0.63 mm), dried, debinded and pre-sintered (up to 1100 degrees C for 2 h), being finally sintered at 1550 degrees C for 2 h. The sintered samples were evaluated by their microstructure, phase composition and relative density. The hardness and Young's modulus of the sintered samples, were evaluated locally, by dynamic nanoindentation varying the indentation loads: 250 mN -> 1960 mN. The three sintered sample' groups showed similar relative density (approximate to 90 %), but different proportions of the three ZrO2 polytypes (monoclinic, tetragonal, and cubic) as crystalline phases in their composition. The microstructure of the sintered groups was characterized by bimodal grain size distributions, with larger grain sizes as yttria concentration increased and, consequently, higher presence of cubic phase and translucency. Vickers hardness of 1023 HV, 921.4 HV and 896.9 HV and fracture toughness of 5.45 MPa m1/2, 4.30 MPa m1/2 and 4.15 MPa m1/2 were obtained for 3Y-TZP, 4Y-PSZ and 5Y-PSZ, respectively, both influenced by relative density.
palavras-chave
OF-THE-ART; ELASTIC-MODULUS; STRENGTH; PEG; INDENTATION; RELIABILITY; PERFORMANCE; HYDROGELS; BEHAVIOR; HARDNESS
categoria
Materials Science; Metallurgy & Metallurgical Engineering
autores
Gomes, PD; Freitas, BX; Alves, MFRP; Olhero, S; Santos, KF; Dávila, JL; Daguano, JKMB; dos Santos, C
nossos autores
Manuel Fellipe Rodrigues Pais Alves
Estudante de doutoramento
Susana Maria Henriques Olhero
Professor AuxiliarProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
The authors thanks CNPq for the financial support receive (grant no. 311119/2017-4 and 407680/2021-7) , FAPERJ (grant E-26/202.997/2017) . We are grateful to Prof. Marcos A. d'Avila for kindly allowing us to use of a rheometer at the Multiusuary Laboratory-UNICAMP. The authors also thank the support of CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) . M.F.R.P. Alves acknowledges the FCT for the PhD grant (2021.06615.BD) .r authors also thank the support of CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) . M.F.R.P. Alves ac-knowledges the FCT for the PhD grant (2021.06615.BD) .