Banca de DEFESA: CAMYLA REGINA DANTAS FERREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : CAMYLA REGINA DANTAS FERREIRA
DATA : 23/02/2018
HORA: 14:00
LOCAL: Sala de reuniões do DEMat
TÍTULO:
PALAVRAS-CHAVES:

Bioceramics, bioinert, bioactive, hydroxyapatite, yttria doped zirconia, ceramic composite.

PÁGINAS: 79
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Due to its excellent mechanical properties such as toughness, mechanical strength and modulus of elasticity similar to that of stainless steel alloys, in addition to low toxicity, zirconia is a ceramic biomaterial with several applications. However, zirconia has low affinity with cells and tissues, since it is a bioinert material, and because of its high mechanical properties in relation to the bone, irregular concentrations of tension can appear, resulting in fracture. Hydroxyapatite, in turn, belongs to the calcium phosphate family and has a high modulus of elasticity, and is present in natural compounds such as hard tissue, bone, dentin and dental enamel, being a bioactive material without adequate mechanical resistance. In order to obtain a material with high fracture toughness and affinity with cells and tissues, zirconia and hydroxyapatite composites were developed and investigated. For this work the zirconia used was doped with 8% of yttria, commercial, and the hydroxyapatite was synthesized by sol-gel method at different temperatures and calcination times (500°C/2h, 500°C/4h, 500°C/6h, 700°C/1h, 700°C/2h, 700°C/4h, 900°C/4h). The samples showed commercial yttria doped zirconia layer followed by composite material layer produced with commercial zirconia and hydroxyapatite calcined at 700°C/4h in the following proportions YSZ/HA 95/5, YSZ/HA 90/10, YSZ/HA 85/15 and YSZ/HA 80/20. The samples were characterized by: X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), BET Method, Archimedes Assay, Vickers Microhardness and Scanning Electron Microscopy (SEM). The XRD results showed the formation of the hydroxyapatite major phase at different temperatures and calcination times, with the formation of the composite materials with surface area and hardness decreasing with increasing presence of hydroxyapatite. The samples YSZ/HA 85/15 and YSZ/HA 80/20, presented the best mechanical behavior with higher fracture toughness values of 9.2 and 9.3 MPa.m1/2 , respectively. The sample YSZ/HA 85/15 with lower apparent porosity (0.60%) and water absorption (0.10%).

MEMBROS DA BANCA:
Presidente - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Interno - 1802888 - FABIANA VILLELA DA MOTTA
Externo à Instituição - MARIA INES BASSO BERNARDI - USP