BIOCERÂMICAS À BASE DE ZrO2-TETRAGONAL OBTIDAS POR SINTERIZAÇÃO VIA FASE LÍQUIDA
BIOCERAMICS BASED ON TETRAGONAL-ZrO2 OBTAINED BY LIQUID PHASE SINTERING
Habibe, Alexandre Fernandes; Souza, Renato Chaves; Maeda, Loriane David; Bicalho, Luiz de Araujo; Barboza, Miguel Justino R.; Santos, Claudinei
http://dx.doi.org/10.4322/tmm.00403005
Tecnol. Metal. Mater., vol.4, n3, p.23-29, 2008
Resumo
Nesse trabalho são avaliadas as propriedades mecânicas de cerâmicas à base de ZrO2 sinterizadas por fase líquida de um potencial biocerâmico para aplicação em sistemas de implantes dentários. Pós de ZrO2 estabilizado com Y2O3 foram misturados com 3%, 5%, 10%, 20% ou 30% em peso de um biovidro do sistema 3CaO.P2O5-MgO-SiO2. Essas misturas de pós foram compactadas e sinterizadas a 1.200°C e 1.300°C, por 120 minutos. Após resfriamento, os corposde- prova foram retificados, lixados e polidos, sendo então submetidos à avaliação de dureza Vickers, tenacidade à fratura e resistência à fratura por ensaio de flexão em quatro pontos. Amostras com menores teores de aditivo e sinterizadas a 1.300°C apresentaram valores médios de dureza de 1170 HV, tenacidade à fratura de 6,3 MPa.m1/2 com resistência à flexão de 453 MPa. Comparativamente, amostras de ZrO2(3%Y2O3) sinterizadas de forma similar apresentaram dureza de 875 HV, KIC de 4,1 MPa.m1/2 e resistência à flexão de 127 MPa, indicando que a presença de fase líquida possibilita reduzir a porosidade do material, promovendo aumento das propriedades mecânicas dos materiais cerâmicos à base de ZrO2.
Palavras-chave
Biomateriais, Caracterização, Citotoxicidade
Abstract
The objective of this work is the evaluation of the mechanical properties of ZrO2 ceramics sintered by liquid phase. Y2O3-stabilized-ZrO2 ceramic powder was mixed at 3%, 5%, 10%, 20% or 30 wt.% of bioglass of 3CaO.P2O5-MgOSiO 2 system. These powder mixtures were compacted and sintered at 1.200°C and 1300°C, for 120 min. After cooling, samples were grinded, polished and evaluated by Vickers hardness, fracture toughness and four-point bending strength. Samples sintered at 1.300°C with low bioglass content showed hardness of 1170 HV, fracture toughness of 6.3 MPa.m1/2 with bending strength of 453 MPa. Comparatively, samples of ZrO2(3%Y2O3) sintered in the similar conditions, showed hardness of 875 HV, KIC of 4.1 MPa.m1/2 and bending strength of 127 MPa, indicating that the presence of liquid phase contributed with the decreasing of porosity, increasing the mechanical properties of the ceramic materials based on ZrO
Keywords
Biomaterials, Characterization, Citotoxicicity
Referências
1 DE AZA, A.H., CHEVALIER, J., FANTOZZI, G. Crack growth resistance of alumina, zirconia and zirconia toughened alumina ceramics for joint prostheses. Biomaterials, v. 23, n. 3, p. 937-45, Feb. 2002.
2 NONO, M.C.A. Cerâmicas à base de zircônia tetragonal policristalina do sistema CeO2-ZrO2 (Ce-TZP). 1990. Tese (Doutorado em Engenharia Mecânica) – Instituto Tecnológico da Aeronáutica, São José dos Campos, 1990.
3 STEVENS, R., Zirconia: second phase particle transformation toughening of ceramics. Transactions British Ceramic Society, v. 80, p 81-85, 1981.
4 STEVENS, R., An introduction to zirconia: zirconia and zirconia ceramics. 2. ed. Twickenham: Magnesium Elektrum, 1986. (Magnesium Elektron Publications, 113)
5 ANUSAVICE, K.J. Phillips: materiais dentários. 11. ed. Rio de Janeiro: Elsevier; 2005.
6 KOHN, D. H., DUCHEYNE, P., AWERBUCH, J. Sources of acoustic emission during fatigue of Ti-6Al-4V: effect of microstructure. Journal of Materials Science, v. 27, n. 6, p.1633-41, 1992.
7 KOHN, D. H.; DUCHEYNE, P.; AWERBUCH, J. Acoustic emission during fatigue of porous-coated Ti-6Al-4V implant alloy. Journal of Biomedical Materials Research, v.26, n.1, p.19-38, Jan. 1992.
8 AMARAL, M.; LOPES, M.A.; SILVA, R.F.; SANTOS, J.D. Densification route of Si3N4-bioglass biocomposites. Biomaterials, v.23, n.3, p. 857-62, Feb. 2002.
9 SANTOS, C., SOUZA, R.C., ALMEIDA, N., ALMEIDA F.A., SILVA, R.R.F.SILVA, FERNANDES, M.H.F.V., Toughened ZrO2 ceramics sintered with a La2O3-rich glass as additive, Journal of Materials Processing technology, v. 200, n 1-3, p.126-32, May 2008.
10 SANTOS, C., SOUZA, R.C., HABIBE, A.F., MAEDA, L.D., Mechanical properties of Y-TPZ ceramics obtained by liquid phase sintering using bioglass as additive, Materials Science and Engineering A, v. 478, n.1-2, p.257-63, Apr. 2008.
11 OLIVEIRA, J.M.; FERNANDES, M.H.; CORREIA, R.N. Development of a new glass ceramic in the system MgO-3CaO. P2O5-SiO2. Bioceramics, v. 5, n.1., p.7-14, Jan. 1997.
12 OLIVEIRA, J. M.; CORREIA, R.N.; FERNANDES, M.H. Effects of Si speciation on the in vitro bioactivity of glasses. Biomaterials, v. 23, n. 2, p.371-9, Feb. 2002.
13 EVANS, A.G.; CHARLES, E.A. Fracture toughness determination by indentation. Journal of the American Ceramic Society, v. 59, n.7-8, p. 371-2, Jul. 1976.
14 GERMAN, R.M. Sintering theory and practice. New York: John Wiley and Sons, 1996.
15 TAYA, M., HAYASHI, S., KOBAYASHI, A.S., YOON, H.S., Toughening of a particulate-reinforced ceramic-matrix composite by thermal residual stress. Journal of the American Ceramic Society, v.73, n.5, p.1382-1391, May 1990.
16 SHI, J.L.; LI, L.; GUO, J.K. Boundary stress and its effect on toughness in thin boundary layered and particulate composites: model analysis and experimental test on T-TZP based ceramic composites. Journal of the European Ceramic Society, v.18, p.2035-2043, 1998.
17 SHI, J.L.; LU, Z.L.; GUO, J.K. Model analysis of boundary residual stress and its effect on toughness in thin boundary layered yttria-stabilized tetragonal zirconia polycrystalline ceramics. Journal of Materials Research, v.15, n.3, p.727-32, Mar. 2000.
18 BASU, B.; VLEUGELS, J.; VAN DER BIEST, O. ZrO2-Al2O3 composites with tailored toughness. Journal of Alloys and Compounds, v.365, n. 1-2, p. 266-70, Feb. 2004.
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