1. Relevance of cold-rolling technology for the texture and anisotropy of EN AW-8011A aluminum alloysJakob Kraner, Kyung Il Kim, Bonghwan Kim, Shae K. Kim, Irena Paulin, 2023, izvirni znanstveni članek Ključne besede: aluminium alloys, cold rolling, SEM-EBSD, textures, anisotropy Objavljeno v DiRROS: 08.03.2024; Ogledov: 71; Prenosov: 32 Celotno besedilo (2,04 MB) Gradivo ima več datotek! Več... |
2. 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: 113; Prenosov: 41 Celotno besedilo (897,18 KB) Gradivo ima več datotek! Več... |
3. Effect of heat treatment on thermal conductivity of additively manufactured AISI H13 tool steelSamo Tome, Blaž Karpe, Irena Paulin, Matjaž Godec, 2024, objavljeni znanstveni prispevek na konferenci Povzetek: AISI H13 is commonly used for tooling, where higher wear resistance, thermal fatigue resistance, or hot toughness is required. Such examples include forging dies, plastic molds, hot shear blades, high-pressure die casting, and extrusion dies. Thus, thermal conductivity is one of the most important factors for hot work tools. Typically, the work cycle of a hot work tool designed for forging consists of four main phases: the forging stroke, with which the die imparts its shape onto the part, a brief pause while the die is reset to its original position, a lubrication phase, and a post lubrication dwell phase. During the forging phase, a significant amount of heat is transferred to the die while it is in contact with the part. This heat must then be dispelled for the part to return to a working temperature. While somewhat different, other hot work processes mentioned above are similar in that the hot work tool gets heated to a high temperature due to the contact with the object of deformation. The process of additive manufacturing (AM) promises better, more efficient tool production with features like conforming cooling channels, which would reduce the thermal fatigue of tools, prolonging tool life. However, the powder bed fusion (PBF) method creates a columnar microstructure, which has a detrimental effect on the thermal conductivity of H13 tool steel. Our investigation focused on the beneficial effect of heat treatment, specifically annealing at different temperatures, on the thermal conductivity of AM-produced H13 parts. Ključne besede: SLM, thermal conductivity, tool steel, heat treatment Objavljeno v DiRROS: 28.02.2024; Ogledov: 81; Prenosov: 43 Celotno besedilo (655,96 KB) Gradivo ima več datotek! Več... |
4. Characterization of hFOB 1.19 cell line for studying Zn-based degradable metallic biomaterialsEva Jablonská, Lucie Mrázková, Jiří Kubásek, Dalibor Vojtěch, Irena Paulin, Tomáš Ruml, Jan Lipov, 2024, izvirni znanstveni članek Povzetek: In vitro testing is the first important step in the development of new biomaterials. The human fetal osteoblast cell line hFOB 1.19 is a very promising cell model; however, there are vast discrepancies in cultivation protocols, especially in the cultivation temperature and the presence of the selection reagent, geneticin (G418). We intended to use hFOB 1.19 for the testing of Zn-based degradable metallic materials. However, the sensitivity of hFOB 1.19 to zinc ions has not yet been studied. Therefore, we compared the toxicity of zinc towards hFOB 1.19 under different conditions and compared it with that of the L929 mouse fibroblast cell line. We also tested the cytotoxicity of three types of Zn-based biomaterials in two types of media. The presence of G418 used as a selection reagent decreased the sensitivity of hFOB 1.19 to Zn2+. hFOB 1.19 cell line was more sensitive to Zn2+ at elevated (restrictive) temperatures. hFOB 1.19 cell line was less sensitive to Zn2+ than L929 cell line (both as ZnCl2 and extracts of alloys). Therefore, the appropriate cultivation conditions of hFOB 1.19 during biomaterial testing should be chosen with caution. Ključne besede: zinc degradable materials, in vitro cytotoxicity testing, hFOB 1.19 osteoblasts Objavljeno v DiRROS: 28.02.2024; Ogledov: 83; Prenosov: 38 Celotno besedilo (1,81 MB) Gradivo ima več datotek! Več... |
5. Solidification Behavior of Fe-6.5Si Alloy Powder for AM-SLM Processing, as Assessed by Differential Scanning CalorimetryDarja Steiner Petrovič, Črtomir Donik, Irena Paulin, Matjaž Godec, Maja Vončina, Martin Petrun, 2023, izvirni znanstveni članek Ključne besede: soft magnetic alloy, differential scanning calorimetry, oxygen, high-temperature phase, microstructure, eutectics Objavljeno v DiRROS: 02.02.2024; Ogledov: 111; Prenosov: 47 Celotno besedilo (9,05 MB) Gradivo ima več datotek! Več... |
6. Predicting the quality of grain refiners from electrical resistance measurements of aluminumMaja Vončina, Irena Paulin, Jože Medved, Mitja Petrič, 2023, izvirni znanstveni članek Ključne besede: Al-Ti-B grain-refiners, quality, TiB2 particles, Al3Ti particles, electrical resistance measurements Objavljeno v DiRROS: 01.02.2024; Ogledov: 125; Prenosov: 51 Celotno besedilo (8,93 MB) Gradivo ima več datotek! Več... |
7. Effects of variated final temperature and workpiece thickness for hot rolling of aluminum alloy EN AW-8011Jakob Kraner, Peter Cvahte, Primož Šuštarič, Tomaž Šuštar, Črtomir Donik, Irena Paulin, Shae K. Kim, Kjung Il Kim, 2023, izvirni znanstveni članek Ključne besede: aluminum alloy, hot rolling, simulations, metallography, mechanical properties Objavljeno v DiRROS: 01.02.2024; Ogledov: 114; Prenosov: 51 Celotno besedilo (5,46 MB) Gradivo ima več datotek! Več... |
8. The influence of the hot-rolling technique for EN AW-8021B aluminium alloy on the microstructural properties of a cold-rolled foilJakob Kraner, Tomaž Smolar, Darja Volšak, Marjana Lažeta, Robert Skrbinek, Damijan Fridrih, Peter Cvahte, Matjaž Godec, Irena Paulin, 2021, izvirni znanstveni članek Ključne besede: aluminium alloys, hot rolling, microstructure, EBSD, burst test Objavljeno v DiRROS: 06.05.2022; Ogledov: 456; Prenosov: 120 Povezava na datoteko |
9. The evolution of microstructure and mechanical properties of Zn-0.8Mg-0.2Sr alloy prepared by casting and extrusionJiří Kubásek, Jan Pinc, Klára Hosová, Markéta Straková, Orsolya Molnárová, Jan Duchoň, David Nečas, Miroslav Čavojský, Matjaž Godec, Irena Paulin, 2022, izvirni znanstveni članek Ključne besede: zinc, magnesium, biodegradable, microstructure, mechanical properties, texture Objavljeno v DiRROS: 06.05.2022; Ogledov: 684; Prenosov: 184 Povezava na datoteko |