Estudos das transformações de fases, propriedades mecânicas e de resistência à corrosão em ligas dos sistemas Ti-Nb e Ti-Nb-Si para aplicações biomédicas

• Autor(a) principal: Tavares, Andrea Macleybiane Gois
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/3491
• topic: Materiais; Ligas de titânio; Materiais biomédicos; Resistência de materiais; Elasticidade; Corrosão e anticorrosivos; Titanatos; Titânio; Nióbio-titânio; Biomedical materials; Corrosion and anti-corrosives; Elasticity; Materials; Titanates; Titanium; Titanium alloys; Niobium-titanium; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA

Researches on alloy elements such as niobium and silicon have been added to titanium alloys as an alternative for new materials to be used in orthopedic implants, once they present biocompatibility and favor reductions in the elasticity modulus. Therefore, the objective of this study was to investigate the phase transformations, mechanical properties and corrosion resistance of the Ti-Nb and Ti-Nb-Si alloys for biomedical applications. The results showed that Si addition is effective to stabilizing the £] phase, which also acts as a ç suppressor, and to produce grain refinement. In all samples, the hardness values increased with the increasing of Si content, while the elastic modulus was reduced in the Ti-15Nb-xSi and Ti-35Nb-xSi alloys; however, for Ti-40Nb-xSi samples increased with the increasing of Si content. Lower elastic moduli were observed in water-quenched Ti-35Nb-xSi alloys, for which tensile tests and corrosion resistance were performed. The increase in Si concentration also produced an increase in the alloys mechanical strength. Ti-35Nb-0,55Si alloy, however, showed brittle mechanical behavior which was related to the presence of silicides, referred as (Ti,Nb)3Si, at the grain boundaries. Corrosion tests showed that the alloys exhibit high resistance in the studied environment. The results suggest that the Ti-35Nb-0,35Si alloys presents the best combination of properties: good mechanical strength, low elastic modulus and excellent corrosion resistance.