Caracterização microestrutural e mecânica da liga Ti25Ta25Nb para aplicações biomédicas

• Autor(a) principal: Pereira Júnior, Adelvam [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155332; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-04-13/000881893.pdf
• topic: Ligas de titanio; Materiais biomédicos; Microestrutura; Titanium alloys

Metallic biomaterials are usually used for restore the function of hard tissues and also are used, for example, in the manufacture of dental prostheses and dental implants. Titanium and its alloys have been used in biomedical applications because of their excellent properties such as high corrosion resistance, biocompatibility and mechanical properties. In orthodontics, it is common to use metallic and non-metallic alloys to produce braces composed by bands, brackets, orthodontic wires and ligatures. Initially in orthodontics, it was common to use nickel-titanium alloys, however due to allergic reactions with nickel in patients, it has began study of the substitution of this element and the development of new titanium alloys containing other elements such as niobium and tantalum. The Ti25Ta25Nb alloy has a lower modulus of elasticity than titanium-β alloys, being, therefore, considered an alloy of great interest for orthodontic applications. Due to this, the present study aims to process the Ti25Ta25Nb alloy, characterizing its microstructure, mechanical properties and resistance to corrosion. For this purpose, the casting of the metals was obtained in an arc melting furnace with an inert atmosphere of argon gas. The obtained ingots were submitted to a homogenization heat treatment (950 ° C for 24 hours with slow cooling in furnace) and solubilization (850 ° C for 2 hours with fast cooling in water) and then cold forged in a rotary forge with subsequent heat treatment of solubilization. At each step of the process a sample was taken for microstructural analysis (optical microscopy and x-rays diffraction). For mechanical characterization (microhardness and tensile test) and corrosion resistance (open circuit potential and potentiodynamic polarization). The samples showed a microstructure with predominance of β phase, microhardness and modulus of elasticity (166 HV and 55 GPa), and ...(Complete abstrac click electonic access below)