Entropy Effects on Mechanical, Corrosion, and Biocompatibility Properties of Nanostructured Ti-Nb-Zr-Ta-Hf Bio-High Entropy Alloys and Ceramics Processed via HPT and SPS

• Grant number: 25/10495-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: March 01, 2026
• End date: February 28, 2027
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: Ricardo Floriano
• Grantee: Payam Edalati
• Supervisor: Motonori Watanabe
• Host Institution: Faculdade de Ciências Aplicadas (FCA). Universidade Estadual de Campinas (UNICAMP). Limeira , SP, Brazil
• Institution abroad: Kyushu University, Japan
• Associated to the scholarship: 23/07884-3 - Processing and characterization of mechanical and biocompatibility properties of (TiZrNbTa)90Cu10-xAgx and (TiZrNbMo)90Cu10-xAgx (X = 0, 2.5, 5.0, 7.5 and 10 at%) multicomponent alloys designed for the biomedical applications, BP.DR

Abstract

The medical device industry increasingly demands materials combining superior mechanical performance and excellent biocompatibility. In this context, high-entropy alloys (HEAs) and high-entropy ceramics (HECs) have emerged as promising candidates due to their unique structural and compositional versatility. This project, developed in collaboration with Kyushu University (Japan), focuses on biocompatible HEAs and HECs (bio-HEAs and bio-HECs) composed exclusively of non-toxic elements.The primary objective is to investigate the effect of configurational entropy and nanostructuring on the mechanical, corrosion, and biocompatibility properties of materials within the Ti-Nb-Zr-Ta-Hf system. The study is divided into main parts: Part 1: Synthesis and analysis of metallic alloys - binary (TiNb), ternary (TiNbZr), quaternary (TiNbZrTa), and quinary (TiNbZrTaHf) - processed via high-pressure torsion (HPT) to induce nanostructuring and phase transformations. Part 2: Fabrication and characterization of corresponding oxide high entropy ceramics - (TiNb)O, (TiNbZr)O, (TiNbZrTa)O, and (TiNbZrTaHf)O - using spark plasma sintering (SPS) after controlled oxidation. The employed methodologies include arc melting, HPT, oxidation treatments, and SPS consolidation. Characterization techniques encompass X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), mechanical property evaluations, corrosion resistance assessments, and biocompatibility testing. This collaborative effort aims to generate new insights into the roles of entropy and grain refinement in determining the multifunctional behavior of advanced biomaterials. The findings are expected to contribute to the development of next-generation materials for orthopedic implants and other biomedical applications. (AU)