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Corrosion and fatigue behaviour of biodegradable iron scaffolds for biomedical applications
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A utilização de scaffolds biodegradáveis permite a regeneração progressiva do tecido ósseo enquanto se degrada de forma controlada, evitando custos e riscos com cirurgias pós-operatórias. Este estudo analisa o comportamento à corrosão, fadiga e fadiga-corrosão de scaffolds de ferro produzidos por manufatura aditiva, com células unitárias Rhombitruncated Cuboctahedron com 10% de densidade, que mimetizam o osso trabecular. Foram aplicadas técnicas como Espectroscopia de Impedância Eletroquímica, Microscópio eletrónico de varrimento, Microtomografia Computorizada, e Espectroscopia de Infravermelho por Transformada de Fourier, para analisar e caracterizar o comportamento à corrosão e mecânico dos scaffolds. Os ensaios de corrosão em fluido corporal simulado (SBF, 37ºC) revelaram a formação de uma película de óxidos, hidróxidos carbonatos e fosfatos na superfície do ferro. Nos ensaios de fadiga compressão-compressão, em SBF, verificou-se uma redução significativa da vida à fadiga dos scaffolds relativamente ao ambiente inerte. Embora a degradação à fadiga-corrosão seja elevada para scaffolders com 10% de densidade, a flexibilidade do processo de manufatura aditiva permite otimizar a densidade e melhorar o desempenho, contribuindo para o desenvolvimento de implantes biodegradáveis seguros e eficazes.
The use of biodegradable scaffolds allows for progressive bone tissue regeneration while degrading in a controlled manner, avoiding the costs and risks associated with post-operative surgery. This study analyses the corrosion, fatigue, and fatigue-corrosion behaviour of iron scaffolds produced by additive manufacturing, with Rhombitruncated Cuboctahedron unit cells with 10% density, which mimic trabecular bone. Techniques such as Electrochemical Impedance Spectroscopy, Scanning Electron Microscopy, Computed Microtomography, and Fourier Transform Infrared Spectroscopy were applied to analyse and characterize the corrosion and mechanical behaviour of the scaffolds. Corrosion tests in simulated body fluid (SBF, 37°C) revealed the formation of a film of oxides, hydroxides, carbonates, and phosphates on the iron surface. In compression-compression fatigue tests in SBF, a significant reduction in the fatigue life of the scaffolds was observed compared to the inert environment. Although fatigue-corrosion degradation is high for scaffolds with 10% density, the flexibility of the additive manufacturing process allows for density optimization and performance improvement, contributing to the development of safe and effective biodegradable implants.
The use of biodegradable scaffolds allows for progressive bone tissue regeneration while degrading in a controlled manner, avoiding the costs and risks associated with post-operative surgery. This study analyses the corrosion, fatigue, and fatigue-corrosion behaviour of iron scaffolds produced by additive manufacturing, with Rhombitruncated Cuboctahedron unit cells with 10% density, which mimic trabecular bone. Techniques such as Electrochemical Impedance Spectroscopy, Scanning Electron Microscopy, Computed Microtomography, and Fourier Transform Infrared Spectroscopy were applied to analyse and characterize the corrosion and mechanical behaviour of the scaffolds. Corrosion tests in simulated body fluid (SBF, 37°C) revealed the formation of a film of oxides, hydroxides, carbonates, and phosphates on the iron surface. In compression-compression fatigue tests in SBF, a significant reduction in the fatigue life of the scaffolds was observed compared to the inert environment. Although fatigue-corrosion degradation is high for scaffolds with 10% density, the flexibility of the additive manufacturing process allows for density optimization and performance improvement, contributing to the development of safe and effective biodegradable implants.
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Manufatura Aditiva Ferro Corrosão Fadiga Fadiga-corrosão Regeneração óssea Additive Manufacturing Iron Corrosion Fatigue Corrosion-fatigue Bone regeneration