EXPLORING FUNCTIONAL GRADIENTS AND DISSIMILAR JOINTS USING METASTABLE BETA TITANIUM ALLOYS

• Grant number: 26/12910-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2026
• End date: August 31, 2030
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Rubens Caram Junior
• Grantee: Carlos Samuel Alves da Silva
• Host Institution: Faculdade de Engenharia Mecânica (FEM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 18/18293-8 - Titanium alloys: phase transformations and additive manufacturing applied to obtaining functionally graded materials, AP.TEM

Abstract

This work proposes the development of a multimaterial structure produced by laser powder bed fusion (L-PBF) additive manufacturing, using the metastable beta alloy Ti-35Nb-6Ta associated with dissimilar layers of Mo, Cr, Ni, and 316L stainless steel. The proposal is based on the need to produce femoral stems with a gradient elastic modulus, aiming to improve the biomechanical compatibility between the implant and bone tissue, as well as to obtain high surface hardness at the stem head, in order to optimize the tribological behavior of the component. The focus of the work is to solve metallurgical challenges related to the joining of dissimilar materials processed by additive manufacturing. To this end, thermodynamic simulations will be used to predict the formation of intermetallic compounds and assist in defining the most suitable intermediate compositions. This study will involve optimizing the processing of Ti-35Nb-6Ta alloy and the fabrication of dissimilar joints between Ti-35Nb-6Ta, Mo, Cr, Ni, and 316L stainless steel by L-PBF. The preparation of these joints will be supported by preliminary arc furnace experiments, aiming to investigate the formation of intermetallic compounds at the produced interfaces. Subsequently, the samples will undergo microstructural characterization, allowing for the evaluation of chemical composition, phases present, crystallographic texture, grain morphology, and the formation of intermetallic compounds. Furthermore, mechanical tests will be performed to evaluate the behavior of the produced joints. As a final step, the intention is to fabricate a reduced-scale model of a multi-material femoral device, with the goal of demonstrating the feasibility of the proposed method. (AU)