1. High temperature oxidation of EN AW 7075 aluminium alloyNejc Velikajne, Tilen Balaško, Jaka Burja, Matjaž Godec, Irena Paulin, 2024, objavljeni znanstveni prispevek na konferenci Povzetek: Aluminium alloys are highly valued for their exceptional strength-to-weight ratio, making them a preferred choice in structural applications. Among these alloys, EN AW 7075 stands out for its superior mechanical properties, finding widespread use in industries such as aerospace, mechanical engineering, and sports equipment. This study investigates the high-temperature oxidation behavior of EN AW 7075 alloy. The gathered results can provide valuable insights into the behavior of the mentioned alloy during the selective laser melting (SLM) process. These results can contribute to a better understanding of how the alloy responds to specific conditions and parameters. SLM is an additive manufacturing technique. The process involves the sequential steps of preheating, melting, and rapid cooling of metal powder. To minimize the influence of oxygen, the build chamber is filled with inert gas. A protective argon atmosphere is continuously maintained. However, despite these precautions, oxidation can still occur, leading to potential issues in the final product. Hence, we examined the oxidation kinetics of the EN AW 7075 alloy in an oxygen atmosphere in the temperature range of 300-500 °C. The findings of this investigation significantly contribute to an understanding of the behavior of the alloy during high-temperature oxidation, particularly for ongoing studies focused on processing Al-Zn-Mg-Cu alloys using the selective laser melting technique. Thermogravimetry was employed to analyze the oxidizing behavior, with three samples subjected to a 6-hour exposure in an oxidizing atmosphere at temperatures of 300, 400, and 500 °C. Surprisingly, no oxidation occurred, as indicated by the negligible and negative changes in mass observed across all samples. Ključne besede: EN AW 7075, high-temperature oxidation, oxide film, selective laser melting Objavljeno v DiRROS: 28.02.2024; Ogledov: 486; Prenosov: 293 Celotno besedilo (897,18 KB) Gradivo ima več datotek! Več... |
2. High-temperature oxidation of boiler steels at 650 °CJaka Burja, Barbara Šetina, Borut Žužek, Tilen Balaško, 2023, izvirni znanstveni članek Povzetek: This study presents a comprehensive investigation of the formation, composition and
behaviour of oxide layers during the high-temperature oxidation of four different steel alloys (16Mo3,
13Cr, T24 and P91) at a uniform temperature of 650 °C. The study is aimed at assessing the oxidation
damage due to short-term overheating. The research combines CALPHAD (CALculation of PHAse
Diagrams) calculations, thermogravimetric analysis (TGA) and advanced microscopy techniques, in-
cluding scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD), to elucidate
the complex mechanisms controlling oxidation kinetics and oxide layer development. CALPHAD
calculations were used to determine the thermodynamically stable phases for each steel type at 650
◦C and different oxygen activities. The results showed different phase compositions, highlighting
the importance of the chromium content in steel for the formation of oxide layers. The different
oxidation kinetics and oxide layer compositions are presented and associated with the increased risk
of material degradation due to overheating. These results have significant implications for industrial
applications, mainly the susceptibility to oxidation of low-alloyed steels like 16Mo3 and 13 Cr and
contribute to a deeper understanding of oxidation processes in steels. Ključne besede: high-temperature oxidation, thermogravimetric analysis, kinetics, CALPHAD, boiler steels, SEM, EBSD Objavljeno v DiRROS: 26.01.2024; Ogledov: 524; Prenosov: 263 Celotno besedilo (12,99 MB) Gradivo ima več datotek! Več... |
3. Selective glucose oxidation to glucaric acid using bimetallic catalysts : lattice expansion or electronic structure effect?Žan Lavrič, Janvit Teržan, Ana Kroflič, Janez Zavašnik, Joanna E. Olszówka, Štefan Vajda, Matej Huš, Miha Grilc, Blaž Likozar, 2024, izvirni znanstveni članek Povzetek: Our study presents a comprehensive approach for the selective oxidation of glucose to glucaric acid (GA) by heterogeneous catalysis. We have synthesized and characterized Au/ZrO2, AuCu/ZrO2 and AuPt/ZrO2 catalysts using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and oxygen pulse chemisorption (OPS) techniques. Combining experimental observations with in-depth density functional theory (DFT) studies, we found that bimetallic catalysts form alloys, which exhibit different characteristics than monometallic counterparts for the given reaction. We performed batch reactions, varying temperature and oxygen pressure, and used the data to construct a predictive microkinetic model. As it turned out, AuPt/ZrO2 showed the highest selectivity, yielding 32 % of GA at 100 °C and 30 barg O2. Our results provide valuable insights for the developing of efficient catalysts and point out the bottlenecks for the oxidation of glucose to GA. Ključne besede: glucaric acid, glucose oxidation, catalyst characterization, density functional theory, microkinetic modelling Objavljeno v DiRROS: 06.12.2023; Ogledov: 572; Prenosov: 248 Celotno besedilo (2,73 MB) Gradivo ima več datotek! Več... |
4. Influence of alumina precursor properties on Cu-Fe alumina supported catalysts for total toluene oxidation as a model volatile organic air pollutantTadej Žumbar, Alenka Ristić, Goran Dražić, Hristina Lazarova, Janez Volavšek, Albin Pintar, Nataša Zabukovec Logar, Nataša Novak Tušar, 2021, izvirni znanstveni članek Ključne besede: alumina precursors, Cu-FeAl12O3 catalysts, heterogeneous catalysis, nanostructures, toulene total catalytic oxidation Objavljeno v DiRROS: 17.11.2022; Ogledov: 867; Prenosov: 392 Celotno besedilo (9,37 MB) Gradivo ima več datotek! Več... |
5. The role of oxygen in new vinification technologies of white and red winesKlemen Lisjak, 2007, doktorska disertacija Ključne besede: winemaking, wines, musts, chemical composition, white wines, red wines, oxygen, oxidation, pressing, hyperreduction, microoxygenation, glutathione, caftaric acid, coutaric acid, fertaric acid, hydroxycinnamates, anthocyanins, polyphenols Objavljeno v DiRROS: 06.09.2022; Ogledov: 865; Prenosov: 280 Povezava na celotno besedilo |
6. Revealing the Pb whisker growth mechanism from Al-alloy surface and morphological dependency on material stress and growth environmentMatic Klug Jovičević, Tim Verbovšek, Patricia Jovičević Klug, Barbara Šetina, Bojan Ambrožič, Goran Dražić, Bojan Podgornik, 2022, izvirni znanstveni članek Ključne besede: aluminum alloy, metallic whiskers, residual stress, crystal growth, oxidation Objavljeno v DiRROS: 06.05.2022; Ogledov: 828; Prenosov: 267 Povezava na datoteko |
7. Photocatalytic, electrocatalytic and photoelectrocatalytic degradation of pharmaceuticals in aqueous media : analytical methods, mechanisms, simulations, catalysts and reactorsBelisa Alcantara Marinho, Luka Suhadolnik, Blaž Likozar, Matej Huš, Živa Marinko, Miran Čeh, 2022, pregledni znanstveni članek Ključne besede: advanced oxidation process, persistent organic compounds, pharmaceutical by- products, degradation mechanism, reactor design, analytical methods Objavljeno v DiRROS: 10.03.2022; Ogledov: 942; Prenosov: 681 Celotno besedilo (11,34 MB) Gradivo ima več datotek! Več... |
8. Effect of surface oxidation on oxidative propane dehydrogenation over chromia : ǂan ǂab initio multiscale kinetic studyMatej Huš, Drejc Kopač, David Bajec, Blaž Likozar, 2021, izvirni znanstveni članek Ključne besede: dehydrogenation, chromium oxide, surface oxidation, propane, multiscale modeling Objavljeno v DiRROS: 03.09.2021; Ogledov: 1327; Prenosov: 960 Celotno besedilo (4,46 MB) Gradivo ima več datotek! Več... |
9. In-situ regeneration of Au nanocatalysts by atmospheric-pressure air plasma : significant contribution of water vaporBin Zhu, Xiao-Song Li, Jing-Lin Liu, Jin-Bao Liu, Xiaobing Zhu, Ai-Min Zhu, 2015, izvirni znanstveni članek Ključne besede: Au catalyst, air plasma, in-situ regeneration, water vapor, CO oxidation Objavljeno v DiRROS: 07.04.2016; Ogledov: 4665; Prenosov: 1096 Povezava na celotno besedilo |
10. In-situ plasma regeneration of deactivated Au/TiO [sub] 2 nanocatalysts during CO oxidation and effect of N [sub] 2 contentHong-Yu Fan, Chuan Shi, Xiao-Song Li, Shuo Zhang, Jing-Lin Liu, Ai-Min Zhu, 2012, izvirni znanstveni članek Ključne besede: gold catalyst, deactivation, plasma regeneration, N [sub] 2 content, CO oxidation Objavljeno v DiRROS: 07.04.2016; Ogledov: 6047; Prenosov: 907 Povezava na celotno besedilo |