Processing and microstructural and mechanical characterization of biodegradable Mg-4,8Y-2,8Gd-0,7Zr (% weigth) alloy for biomedical applications

Author(s)

Viviane Lima Freitas da Silva

• Document type: Master's Dissertation
• Press: Lorena.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de Lorena (EEL/ASDI)
• Defense date: 2020-09-11

Examining board members

Carlos Angelo Nunes; Célia Regina Tomachuk dos Santos Catuogno; Ana Paula Rosifini Alves Claro; Haroldo Cavalcanti Pinto

• Advisor: Carlos Angelo Nunes

Abstract

Metal alloys are commonly used in biomedical applications when properties such as high strength and high fracture toughness are required. Currently, stainless steels, titanium and cobalt-chromium alloys are the most used metallic materials as biomaterials. However, these alloys are unsuitable for applications aimed at tissue regeneration, which makes room for the development of materials that meet these requirements. In this context, magnesium and its alloys have shown promising properties such as good biocompatibility, exceptional rate of biodegradation and Young\'s modulus closer to that of cortical bone, in addition to high strength after adequate processing. Research has shown that magnesium alloys composed of zirconium and rare earths, generally, have desirable mechanical properties for biomedical applications. Therefore, in this work, taking the Mg-4.8Y-2.8Gd-0.7Zr (% mass) alloy as the object of study, a thermomechanical processing route is proposed aiming at the production of sheets. Through the study, the appropriate thermomechanical processing parameters are defined and microstructural and mechanical characterization of the alloy is performed. After homogenization heat treatment (525°C for 12 h), hot rolling (500°C) for the production of 3 mm thick sheets and aging treatment (200°C for 200 hours), the alloy showed its best performance in terms of mechanical properties. In this condition, the alloy proved to be competitive when compared to other Mg-Y-REE-Zr alloys. (AU)

• FAPESP's process: 18/20375-2 - Processing and microstructural and mechanical characterization of the biodegradable alloy Mg-4,8Y-2,8Gd-0,7Zr (% mass) for biomedical applications
• Grantee: Viviane Lima Freitas da Silva
• Support Opportunities: Scholarships in Brazil - Master