Comparison of Printing Strategies in In-Situ Alloying through Laser Additive Manufacturing of Ti-15Nb Alloy with Low Elastic Modulus.

• Grant number: 23/13766-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2024
• End date: December 31, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Transformation Metallurgy
• Principal Investigator: Lucas Barcelos Otani
• Grantee: José Matheus Queiroz Rodrigues
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 18/18293-8 - Titanium alloys: phase transformations and additive manufacturing applied to obtaining functionally graded materials, AP.TEM

Abstract

The use of Ti-6Al-4V alloy as biomaterial is more convenient among Ti alloys due to its large-scale production for aeronautical applications worldwide. But it is well known that Ti-6Al-4V alloy may be detrimental to the patient's health (due to Al and V toxicity) and does not have the most suitable properties. The increase in the life expectancy makes necessary the scientific and technological development of the metallic biomaterials, mainly those with application in orthopedics. The metallic alloys currently used in Brazil have much greater elastic modulus (E) than that of human bone (E = 10 to 30 GPa), such as: stainless steel (200 GPa), Co-Cr alloys (220 GPa), Ti-6Al-4V (110 GPa) and the search for new alloys with better mechanical and chemical biocompatibility is required. The b-Ti alloys (bcc) present the best mechanical biocompatibility (elastic modulus, in the range of E = 55 to 80 GPa) and chemical (better corrosion resistance, cell adhesion and osseointegration). Although more expensive by the addition of noble elements to Ti, the implant itself is not the most expensive in a surgery, and when we treat the patient's health, the price of the material should not be a point of discussion, but rather always the best material possible.The present project aims to compare two different strategies through laser additive manufacturing, the microstructure and properties of a Beta Ti-15Nb Alloy (weight%) obtained through arc fusion and through laser powder bed fusion (LPBF) with low elastic modulus looking for a low elastic modulus value (~60 GPa). Pure Ti (c.p.) processed by different processing routes (Arc Melting in Copper Mold and Selective Laser Melting) will be compared with one or more b-Ti alloys (one will be the Ti-15Nb alloy) with different contents of b-stabilizing elements, and possibly forming different combinations of phases (a, a´, b, a", w,) resulting microstructure. A combination of parameters in laser additive manufacturing by SLM will be sought in order to optimize the microstructure and properties, aiming at the reduced elastic modulus E (GPa).