Cryogenic, vacuum, and inert-gas preparation environments for multi-scale studies of Naval materials systems
Abstract
Controlled cryogenic temperatures, inert-gas environments, and vacuum compatibilities are critical for property measurements, sample preparation and characterization techniques. For materials that are chemically reactive or temperature sensitive, exposure to ambient temperatures and atmosphere can destroy a sample, alter a specific reaction stage or compromise an experiment. Hydrogen (H-) adsorption and diffusion, hydrogen embrittlement, humidity from the atmosphere and related corrosion or oxidation processes can compromise experimental investigations. This is important for small samples, micrometer or nanometer scale, which are common in high-resolution microscopies, i.e., atom probe tomography (APT) or transmission- or scanning electron microscopies (TEM or SEM). We implement acustom-designed unique glove box system with high-purity inert-gas environments, liquid nitrogen workstations and load locks for cryo-vacuum sample transfer to process, image, and analyze specimens at 78 K in vacuum or in a protective inert-gas atmosphere, enabling multi-scale, and multi-modal imaging and analysis, without exposure to atmosphere or ambient temperatures via cryo-vacuum preparation and transfer systems.This cryogenic and inert-gas system permits:1.Uninterrupted cryogenic sample cooling for experiments, sample preparation and cryogenic sample transfer at ~78 K.2.A high-purity inert-gas environment with argon or nitrogen for protecting reactive materials and preventing contamination from humidity & oxidation.3.Effective use of isotopic labeling, D or O, by minimizing cross-contamination for studying adsorption, embrittlement, & corrosion reactions,4.Rapid sample cooling to 78 K for arresting a specific reaction.5.Load locks for vacuum- and high-vacuum, and cryo-compatible transfer shuttles to move samples among multi-scale characterization and microscopy techniques, i.e., cryo-FIB, cryo-SEM, cryo-TEM, and cryo-APT.Relevance to Navy research: We employ a controlled cryogenic and inert-gas environment glove box system for Naval materials studies. The quantitative study of hydrogen adsorption, H-embrittlement and H-induced cracking by quantitative mapping of H distributions w.r.t. to microstructural elements: dislocations, micro-cracks, crack tips, grain boundaries, second-phase precipitates. Cryogenic cooling during specimen preparation, cryo-specimen transfer, and cryogenic experimental characterization to minimize diffusion and trap H atoms in steel microstructures. H or D charging in controlled environments using H or D as probes to find diffusion paths and trapping sites to elucidate H embrittlement in high-Ni and high-Mn steels, their weldments, and additively manufactured (AM) components. Increased interest in materials and manufacturing processes for liquefied natural gas infrastructure include high-Ni and high-Mn steels, requiring improved understanding ofcorrosion and embrittlement processes in aqueous and saline environments. In AM, surface contamination and surface oxidation of power particles limit the shelf-lives of powders. The resulting microstructural defects can adversely affect manufacturing processes and resulting properties. The controlled environment research platform proposed will aid developing an understanding of surface alterations in atmospheric corrosion and mitigation strategies for AM processed steels, Al- and Ti-based alloys. This cryogenic and environmentally controlled preparation and transfer chamber is indispensable for the study of surface processes and Li migration in cathode materials for Li-ion batteries, where Li is highly reactive with a high mobility at and above RT. Cryogenic cooling and inert-gas environment are beneficial for studying the structure and processes during charge cycling of battery materials. Furthermore, the study of corrosion processes, aqueous and saline corrosion, at ambient temperatures and higher-temperature oxidation reactions, will beimproved.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 29, 2023
- Source ID
- N000142312593
Entities
People
- David N. Seidman
Organizations
- Northwestern University
- Office of Naval Research
- United States Navy