Caracterização mecânica de ligas do sistema Ti-Zr para aplicação em implantes dentários
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Data
2022-03-04
Autores
Macedo Filho, Vanderlei Guilherme de
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Universidade Estadual Paulista (Unesp)
Resumo
Ligas de titânio são empregadas na fabricação de implantes na área biomédica devido suas propriedades como biocompatibilidade e resistência à corrosão em fluidos corpóreos, também boa resistência mecânica e baixo módulo de elasticidade. As ligas mais adequadas contém elementos em solução sólida que melhoram suas propriedades, além de diminuir sua temperatura de transformação de fase. O Zircônio quando adicionado ao Titânio, incrementa suas propriedades e atua como elemento estabilizador, além da vantagem de ser considerado neutro. Neste trabalho foram produzidas amostras de Ti-Zr com respectivamente 25, 50 e 75% em massa de Zr visando aplicações biomédicas. As ligas foram produzidas por fusão a arco em atmosfera inerte, conformadas mecanicamente por “Cold Swaging” e homogeneizadas. A caracterização de composição química e estrutural foram feitas por Espectroscopia de Energia Dispersiva e por ensaio de Difração de Raios X. As caracterizações Microestrutural e Mecânica foram realizadas por meio de Microscopia Ótica, Microscopia Eletrônica de Varredura e ensaio normalizado de Microdureza e Tração Uniaxial. Os resultados obtidos comprovam boa estequiometria e homogeneidade da liga. A análise estrutural indica a coexistência das fases α e α’ com estrutura cristalina hexagonal compacta. Os resultados obtidos indicam que concentrações de Zr até cerca de 50% em massa proporcionam aumento na resistência mecânica e pequena diminuição no módulo de elasticidade. A partir de 50% em massa, o Zr diminui a resistência mecânica do sistema e aumenta levemente o módulo de elasticidade. Para a concentração de 75% em massa não foi observado escoamento na ruptura. O módulo de elasticidade na amostra Ti-25Zr ficou em 101,5GPa, valor satisfatório para a aplicação em implantes.
Titanium alloys are used in the manufacture of implants in the biomedical area due to their properties such as biocompatibility and corrosion resistance in body fluids, as well as good mechanical strength and low elastic modulus. The most suitable alloys contain elements in solid solution that improve their properties, in addition to lowering their phase transformation temperature. Zirconium, when added to Titanium, increases its properties and acts as a stabilizing element, in addition to the advantage of being considered neutral. In this work Ti-Zr samples were produced with respectively 25, 50 and 75% by mass of Zr aiming biomedical applications. The alloys were produced by arc melting in an inert atmosphere, mechanically formed by “Cold Swaging” and homogenized. The characterization of chemical and structural composition were performed by Energy Dispersive Spectroscopy and by X-Ray Diffraction test. The Microstructural and Mechanical characterizations were performed by means of Optical Microscopy, Scanning Electron Microscopy and standardized test of Microhardness and Uniaxial Traction. The results obtained show good stoichiometry and homogeneity of the alloy. The structural analysis indicates the coexistence of the α and α' phases with a hexagonal compact crystal structure. The results obtained indicate that concentrations of Zr up to about 50% by mass provide an increase in mechanical strength and a small decrease in the modulus of elasticity. From 50% by mass, Zr decreases the mechanical resistance of the system and slightly increases the modulus of elasticity. For the concentration of 75% by mass, no flow at rupture was observed. The modulus of elasticity in the Ti-25Zr sample was 101.5GPa, a satisfactory value for application in implants.
Titanium alloys are used in the manufacture of implants in the biomedical area due to their properties such as biocompatibility and corrosion resistance in body fluids, as well as good mechanical strength and low elastic modulus. The most suitable alloys contain elements in solid solution that improve their properties, in addition to lowering their phase transformation temperature. Zirconium, when added to Titanium, increases its properties and acts as a stabilizing element, in addition to the advantage of being considered neutral. In this work Ti-Zr samples were produced with respectively 25, 50 and 75% by mass of Zr aiming biomedical applications. The alloys were produced by arc melting in an inert atmosphere, mechanically formed by “Cold Swaging” and homogenized. The characterization of chemical and structural composition were performed by Energy Dispersive Spectroscopy and by X-Ray Diffraction test. The Microstructural and Mechanical characterizations were performed by means of Optical Microscopy, Scanning Electron Microscopy and standardized test of Microhardness and Uniaxial Traction. The results obtained show good stoichiometry and homogeneity of the alloy. The structural analysis indicates the coexistence of the α and α' phases with a hexagonal compact crystal structure. The results obtained indicate that concentrations of Zr up to about 50% by mass provide an increase in mechanical strength and a small decrease in the modulus of elasticity. From 50% by mass, Zr decreases the mechanical resistance of the system and slightly increases the modulus of elasticity. For the concentration of 75% by mass, no flow at rupture was observed. The modulus of elasticity in the Ti-25Zr sample was 101.5GPa, a satisfactory value for application in implants.
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Palavras-chave
Ligas de titanio, Ligas de zircônio, Conformação de metais, Conformação mecânica, Metais - Deformação, Implantes dentários, Titanium zirconium alloys, Mechanical forming, “Cold swaging”, Rotary forging,, Dental implants