An In-Depth Analysis of Hydrogen Embrittlement Mechanisms in Titanium Alloys Using Atom Probe Tomography

• Grant number: 24/00376-5
• Support Opportunities: Scholarships abroad - Research
• Start date: July 05, 2024
• End date: July 04, 2025
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Eric Marchezini Mazzer
• Grantee: Eric Marchezini Mazzer
• Host Investigator: Baptiste Gault
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Imperial College London, England

Abstract

Ti and its alloys hold a significant role as structural materials in petrochemical, aerospace, and biomedical applications. Their susceptibility to hydrogen embrittlement (HE), resulting from hydride formation or hydrogen in solution, is a well-recognized challenge. Various mechanisms have been proposed to elucidate HE in Ti alloys, yet accurately quantifying and visualizing hydrogen proves challenging due to its low weight and the lack of an electron in the outer shell, impeding detection in advanced characterization methods such as Transmission Electron Microscopy (TEM). Atom Probe Tomography (APT) stands out as the sole technique currently capable of pinpointing and quantifying hydrogen within a microstructure with sub-nanometer spatial resolution. However, utilizing APT for this purpose introduces the challenge of preventing hydrogen introduction during sample preparation, which is a concern extensively documented in the literature. Professor Baptiste Gault and his APT group have innovatively addressed this issue by developing a cryogenic method for sample preparation when involving hydrogen. Their research demonstrates the method's effectiveness in preventing hydrogen introduction from the environment, allowing them to revisit and clarify unresolved mechanisms related to hydrogen embrittlement in alloys. This project aims to utilize the expertise of the group in cryogenic sample preparation using cryo plasma Focused Ion Beam (cryo-PFIB) and APT analysis, interconnected with metallurgy of Ti alloys. The objective is to understand how hydrogen interacts with the microstructure in dual-phase commercially available Ti-6Al-4V (Ti64) and Ti-6Al-2Sn-4Zr-6Mo (Ti6246), in different conditions, using a combination of APT and TEM. The ultimate goal is to elucidate hydrogen embrittlement mechanisms in these alloys and the interaction of hydrogen with other elements, allowing the design of high performance Ti alloys, which can be applied in hydrogen environment.