Review
Metallurgy & Metallurgical Engineering
James L. Smialek
Summary: This article reviews key factors related to protective alumina scale adhesion and highlights critical experiments. Different mechanisms are discussed and the chemical bond explanation is found to be the most plausible. Control of sulfur segregation is essential for scale adhesion. The principles presented in this article are consistent with both historical and recent industrial successes.
OXIDATION OF METALS
(2022)
Article
Metallurgy & Metallurgical Engineering
Khalil Rehman, Naicheng Sheng, Shigang Fan, Shijie Sun, Guicheng Hou, Yizhou Zhou, Xiaofeng Sun
Summary: Ni-based superalloys added with higher concentrations of single-doped Hf or co-doped Hf/Y were prepared and their oxidation properties were investigated. The co-doped alloy showed a higher oxidation rate but had better scale adhesion. The Hf-doped alloy had a lower oxidation rate and better scale adhesion at lower temperatures but had a shorter lifetime at higher temperatures.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Ashok Vayyala, Ivan Povstugar, Dmitry Naumenko, Willem J. Quadakkers, Heike Hattendorf, Joachim Mayer
Summary: The oxidation behavior of a ferritic steel Fe-23Cr-0.5Mn-0.6 Nb-0.1Ti (at%) was studied at 800 degrees C. The oxidation kinetics and oxide scale microstructure formed in different gas environments were investigated. Multilayered oxide scales were formed in all environments, and the role of oxygen activity in governing the oxidation kinetics and oxide scale microstructure was identified.
Review
Materials Science, Multidisciplinary
Xingfan Zhang, Peiru Zheng, Yingjie Ma, Yanyan Jiang, Hui Li
Summary: This review provides an overview of the research progress in understanding the atomic-scale oxidation mechanisms, highlighting the importance of computational techniques. By modeling and predicting the evolution of surface structures during oxidation, precise control of the oxidation processes can be achieved, guiding the synthesis of novel oxide materials.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Daniel Scheiber, Erwin Povoden-Karadeniz, Ernst Kozeschnik, Lorenz Romaner
Summary: Simulations are used to predict the dissolved solute contents in multi-component Mo-based alloys and successfully predict the grain boundary enrichment after heat treatment.
Article
Materials Science, Multidisciplinary
Chuhan Sha, Limei Yang, Julie M. Cairney, Jianqiang Zhang, David J. Young
Summary: Fe-30Cr (wt%) alloy was exposed to Ar-0.5%SO2 and Ar-10%H2O-0.5%SO2 gases at 650 degrees C, forming Cr2O3 scales. Sulphur enrichment and scattered Cr-sulphides were observed at the scale-alloy interface in dry SO2 for 20 h, along with internal Cr-sulphide precipitates. After 100 h, sulphur disappeared from the interface, while more internal Cr-sulphides were produced. In wet SO2, sulphur enrichment and Cr-sulphides were maintained in both times, but no internal sulphidation was seen. Atom probe analysis revealed sulphur enrichment on chromia grain boundaries in both gases, more pronounced in wet SO2. These effects are discussed in terms of chromia grain boundary diffusion.
Article
Materials Science, Multidisciplinary
Bangyang Zhou, Jian He, Hui Peng, Jingyong Sun, Hongbo Guo
Summary: This study investigated the cyclic oxidation behavior of two-phase Ni-30Al alloys with varying Hf contents at 1100 degrees C. It was found that the oxidation rate increased significantly with higher Hf content due to severe internal oxidation. Additionally, the microstructures of oxide scales formed on the alloys varied depending on the locations and Hf concentrations, suggesting different oxidation mechanisms and behaviors.
MATERIALS CHARACTERIZATION
(2022)
Article
Chemistry, Multidisciplinary
Kate Reidy, Wouter Mortelmans, Seong Soon Jo, Aubrey N. Penn, Alexandre C. Foucher, Zhenjing Liu, Tao Cai, Baoming Wang, Frances M. Ross, R. Jaramillo
Summary: Oxidation of transition metal dichalcogenides(TMDs) is easily occurs under various conditions. Understanding the oxidation processes is necessary for successful handling and fabrication of TMD devices. In this study, we examined the atomic-scale oxidation mechanisms of MoS2, the most widely studied TMD. Our findings show that thermal oxidation results in α-phase crystalline MoO3 with sharp interfaces, voids, and crystallographic alignment with the underlying MoS2. Experiments with remote substrates reveal that thermal oxidation proceeds via vapor-phase mass transport and redeposition, which poses a challenge in forming thin, conformal films. Oxygen plasma accelerates the oxidation kinetics, leading to the formation of smooth and conformal oxides. The resulting amorphous MoO3 can be grown with subnanometer to several-nanometer thickness, and we calibrated the oxidation rate for different instruments and process parameters. These quantitative results provide guidance for managing the atomic-scale structure and thin-film morphology of oxides in the design and processing of TMD devices.
Review
Microbiology
Christos Gogou, Aleksandre Japaridze, Cees Dekker
Summary: The process of DNA segregation in bacteria involves various mechanisms such as pushing and pulling, while some bacteria rely on entropic forces for chromosome de-mixing. Understanding these mechanisms is crucial for genome segregation research.
FRONTIERS IN MICROBIOLOGY
(2021)
Review
Chemistry, Physical
Soliu Oladejo Ganiyu, Carlos A. Martinez-Huitle, Mehmet A. Oturan
Summary: The knowledge of electrochemical advanced oxidation processes (EAOPs) mechanisms has evolved over the past three decades, aided by advances in analytical and spectrometric techniques. The type, nature, and quantity of reactive species generated in EAOPs are controlled by various factors, and their accurate identification is crucial for understanding their reactivity. The potency and reactivity of oxidants generated in EAOPs are similar regardless of the technique used, except in the case of heterogeneous and homogeneous hydroxyl radicals.
CURRENT OPINION IN ELECTROCHEMISTRY
(2021)
Article
Physics, Fluids & Plasmas
D. Hernandez-Delfin, D. R. Tunuguntla, T. Weinhart, R. C. Hidalgo, A. R. Thornton
Summary: This study reveals the segregation mechanisms of granular mixtures with different shapes under shear. Two distinct segregation mechanisms driven by relative overstress are identified, and a competition between kinetic and gravity effects is observed for nonspherical particles.
Article
Materials Science, Multidisciplinary
Damian Migas, Bartosz Chmiela, Hanna Myalska-Glowacka, Grzegorz Moskal, Krzysztof Matus, Radoslaw Swadz
Summary: The study investigates the individual role of yttrium and Y-related phases during oxidation of Co-based alloys. It reveals that the addition of yttrium improves the oxidation resistance of the alloys, especially under cyclic conditions. The yttrium-containing oxide areas within the oxide scale correspond to the original yttrium-rich particles in the alloy.
Article
Polymer Science
Yunho Ahn, Xavier Colin, Guido Roma
Summary: Understanding the degradation mechanisms of aliphatic polymers by thermal and radio-oxidation is crucial for assessing their lifetime in industrial applications. This study focuses on polyethylene and shows that hydroxyl radicals play a key role in the decomposition of hydroperoxides, proposing more favorable reaction paths. These findings could lead to improvements in current kinetic simulations of polyethylene radio-oxidation.
Article
Energy & Fuels
Kata Kurgyis, Johannes Hommel, Bernd Flemisch, Rainer Helmig, Holger Ott
Summary: Understanding the influence of injection water composition on displacement efficiency is essential for enhanced oil recovery in reservoir engineering. This study implemented two potential mechanisms in a flow simulator to explicitly describe low-salinity effects, aiming to design and interpret experiments, and upscale results. Results indicated a minimum required core length and characteristic fingerprint in chemical water composition changes for identifying the leading low-salinity mechanism.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Chemistry, Physical
Md Shahriar Nahian, Rahul Jayan, Md Mahbubul Islam
Summary: The understanding of mechanistic differences between Na-S and Li-S batteries is critical for designing high-performance cathode materials. Anchoring materials play a crucial role in overcoming performance-limiting factors. This study explores the role of anchoring materials on the polysulfide chemistry in Na-S and Li-S batteries, revealing important insights for the design of cathode materials in metal-sulfur batteries.