this study compared Zr-Mo alloys with commercial metallic biomaterials. it was observed that the Zr-Mo alloys exhibited favourable mechanical properties, particularly the Zr-10Mo alloy, which showed the highest strength to Young's modulus ratio among all evaluated metals. these alloys also exhibited the lowest magnetic susceptibilities, which are important for magnetic resonance imaging (MRi). However, both Zr-and ti-based metals yielded comparable artifacts. it was concluded that the magnetic susceptibility must differ considerably to afford significantly improved MRI quality owing to the increased importance of non-susceptibility-related artifacts when comparing materials with relatively similar magnetic susceptibilities. Metals are still competitive with other classes of materials in the application and development of medical implants in various fields of medicine, such as orthopaedics, neurology, cardiology, and dentistry. Owing to their combined properties, including strength and toughness, and the possibility of employing cost-effective manufacturing processes, metals are typically the best biomaterial choice when compared to ceramics and polymers, as well as composites. The use of metallic devices in the human body is usually required for the replacement and stabilization of damaged bone tissues in orthopaedic practice. The classical examples of such applications include temporary plates and screws, and permanent total hip replacements. Other applications include usage in vascular stents, aneurysm clips, pacemakers, dental implants, wire sutures, etc. 1-3. Despite being similar to Ti alloys, particularly in their physical metallurgy and other properties 4 , Zr-based alloys have received comparatively little attention as biomaterials. Zr and its alloys exhibit excellent biocompatibility, good corrosion behaviour, and favourable mechanical properties 5-11. Specifically, these alloys are suitable for applications in orthopaedic and dentistry owing to their low Young's modulus. A major issue associated with using metallic materials in long-term implants is the mismatch between the bone and the employed device. Rigid implants can promote the stress shielding effect and cause bone resorption, strongly affecting the medium-to long-term quality of the surgical intervention 12. Accordingly, alloys with a low Young's modulus have been targeted for this type of application 13,14. In this regard, Zr alloys are similar to Ti alloys. For instance, Guo et al. 10 reported a Young's modulus of only 44 GPa for a β-type Zr-12Nb-4Sn alloy, which is relatively close to that of human cortical bone (around 20 GPa 15) and is similar to as the best results reported for Ti alloys 16. More recently, increasing interest in Zr and its alloys has been justified by their reduced magnetic susceptibility, which has been claimed to reduce the magnetic resonance imaging (MRI) artifacts 7,10,11,17,18. MRI is a powerful non-invasive tool for medical diagnosis that relies on the nuclear magnetic resonance phenomenon. It presents a high spatial...

ResumoO zircônio metálico possui alta resistência à corrosão, alto ponto de fusão, boa resistência mecânica e baixa capacidade de absorção de nêutrons. Por esse motivo, grande parte do zircônio metálico produzido é utilizado no setor nuclear como material de revestimento interno de reatores. Além disso, estudos recentes mostram que ligas de zircônio apresentam boa biocompatibilidade e baixa susceptibilidade magnética, características promissoras que viabilizam ao seu uso como biomaterial. No presente trabalho, foram estudadas ligas do sistema Zr-Mo, obtidas por meio da fusão em forno a arco voltaico utilizando atmosfera inerte, laminadas a quente, homogeneizadas, solubilizadas e resfriadas em três meios distintos: em água, ar e forno. A caracterização foi feita por meio das técnicas de microscopia de luz visível, microscopia eletrônica de varredura, difração de raio-x, quantificação dos elementos químicos, medidas de dureza Vickers, módulo de elasticidade e susceptibilidade magnética. Os resultados indicam a estabilização da fase β das ligas resfriadas em ar e em água a partir da composição Zr-7,5Mo. A formação de uma microestrutura eutetóide que ocorre de maneira lenta, presente apenas na liga Zr-15Mo que foi solubilizada a 1200 °C e resfriada em forno. Os menores valores de módulo de elasticidade foram obtidos para a liga de composição Zr-7,5Mo independente do tratamento térmico imposto, devido a maior presença da fase β em sua microestrutura. A propriedade de susceptibilidade magnética apresentada pelas ligas do sistema Zr-Mo, exibiu um valor muito menor quando comparada com outros biomateriais, apresentando grande vantagem em exames de ressonância magnética, por amenizar a presença de artefatos.Palavras chaves: Zircônio, Ligas de zircônio, Biomateriais.