resumo
Direct ink writing (DIW) is an extrusion-based additive manufacturing technique, which uses a layer-by-layer deposition of an ink, usually containing high solid loads and low concentration of additives, to provide plasticity and structural stability for the construction of near-net-shaped pieces. In this work, a zirconia stabilized with 5 mol% Y2O3 colloidal ink was developed aiming to obtain dense prototypes, partially translucent, with potential for making dental prostheses. Cylindrical pieces (& Oslash; 20 mm x 2.5 mm), prismatic bars (55 x 5 x 4 mm) and 3-element dental prostheses were printed based on Computer-aided design (CAD) models, using a printing speed of 10 mm.s-1 and a nozzle with & Oslash; 0.25 mm. The printed samples were dried at strictly controlled conditions, debinded using an optimized thermal cycle, and sintered at 1600 degrees C-2 h. The sintered parts were characterized by X-ray diffraction, scanning electron microscopy, Vickers hardness, fracture toughness and bending strength. Concerning dental prosthesis, a post-processing finishing strategy was performed on presintered bodies to highlight the anatomical details. After sintering, samples presented relative density around 94-95 %, Vickers hardness, fracture toughness and Young Modulus of 12.7 +/- 0.3GPa, 5.31 +/- 0.21 MPa.m1/2 and 195.4 +/- 45 GPa, respectively. A characteristic strength (sigma 0) of 303 MPa was attained, which is above the requirements for its application as ceramic single-unit dental prostheses. A critical analysis of the technological difficulties of this 3D printing technique for manufacturing dental prostheses is presented, while future directions are addressed.
palavras-chave
STABILIZED TETRAGONAL ZIRCONIA; FRACTURE-TOUGHNESS; FLEXURAL STRENGTH; ELASTIC-MODULUS; CERAMICS; HARDNESS; INDENTATION; PHASE; PARTS
categoria
Engineering
autores
dos Santos, C; Baltazar, J; Alves, MFRP; Olhero, SM
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
This work was supported by the project "TAMAZ3D- Development of a Decision Support Tool for Additive Manufacturing of Alumina- Zirconia 3-D structures" (POCI-01-0145-FEDER-030493/PTDC/EME- EME/30493/2017). The project CICECO- Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) is also acknowledged. S. M. Olhero acknowledges Foundation for Science and Technology (FCT) for CEECIND/03393/2017 contract. C. Santos thankful for financial support received from Brazilian agencies, FAPERJ (Grants E- 26-201.476/2014 and E26-202.997/2017) and CNPq (Grant 311.119/2017-4). M.F.R.P. Alves acknowledges the FCT for the PhD grant (2021.06615. BD).