TY - CONF A1 - Han, Ying A1 - Radners, J. A1 - von Hartrott, P. A1 - Skrotzki, Birgit T1 - Aluminium high temperature fatigue T2 - Tagungsband der FVV-Informationstagung - Frühjahrstagung 2022 - Würzburg N2 - The studied aluminium alloy is EN AW-2618A (2618A). It is very widely used for exhaust gas turbo-charger compressor wheels. Due to long operating times, high cycle fatigue (HCF) and material aging under the influence of temperatures up to 230 °C is particularly relevant for the wheels. The wheels are typically milled from round wrought blanks. From such round blanks, different testpieces are extracted and a comprehensive series of HCF tests is conducted at room temperature. The tests investigate the materials fatigue performance in the T61 state for two load-ratios, namely R = -1 and R = 0.1. Additionally, two overaged material states are tested, accounting for the aging process the material undergoes during long operating times at high temperatures. The experimental results are evaluated and compared to each other. Furthermore, the design process of notched specimens is presented. With the notched specimens, it is aimed to quantify the notch sensitivity of the material. Relating thereto, two potential model parameters for the fatigue lifetime model are introduced. Finally, the extended research data management in this project is highlighted and its advantages for sustainable use in material science and engineering applications are shown. N2 - In diesem Projekt wird die Aluminiumlegierung EN AW-2618A (2618A) untersucht, welche sehr verbreitet in Verdichterrädern von Abgasturboladern zum Einsatz kommt. Hochzyklische Ermüdung und Werkstoffalterung bei Temperaturen von bis zu 230 °C ist bei Abgasturboladern aufgrund der langen Einsatzzeiten besonders relevant. Die Verdichterräder werden typischerweise aus geschmiedeten Rohlingen gefräst. Aus entsprechenden Rohlingen werden im Rahmen des Projekts eine Vielzahl von Proben mit unterschiedlichen Geometrien entnommen. Die Proben werden unter verschiedenen Prüfbedingungen in hochzyklischen Ermüdungsversuchen bei Raumtemperatur getestet. Zum einen wird das Ermüdungsverhalten des Werkstoffs im T61-Zustand für die zwei Belastungsverhältnisse R = -1 und R = 0,1 untersucht. Zum anderen werden zwei überalterte Materialzustände getestet. Damit soll dem Alterungsprozess Rechnung getragen werden, den das Material während langer Betriebszeiten bei hohen Temperaturen durchläuft. Die experimentellen Ergebnisse werden evaluiert und miteinander verglichen. Darüber hinaus wird der Entwurfsprozess von gekerbten Probengeometrien dokumentiert. Die gekerbten Proben sollen Aufschluss über die Kerbempfindlichkeit des Werkstoffs geben. In diesem Zusammenhang werden zwei mögliche Modellparameter für das zu entwickelnde Lebensdauermodell vorgestellt. Abschließend wird das erweiterte Forschungsdatenmanagement des Projekts beleuchtet und seine Vorteile für die nachhaltige Nutzung in materialwissenschaftlichen und ingenieurtechnischen Anwendungen aufgezeigt. T2 - FVV Frühjahrstagung 2022 CY - Würzburg, Germany DA - 31.03.2022 KW - EN AW-2618A KW - High cycle fatigue KW - Aluminium alloy PY - 2022 IS - FVV Publikationen Heft R602 SP - 617 EP - 634 PB - Forschungsvereinigung Verbrennungskraftmaschinen (FVV) CY - Frankfurt am Main AN - OPUS4-54622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radners, Jan A1 - Han, Ying A1 - von Hartrott, Philipp A1 - Skrotzki, Birgit T1 - Aluminum High Temperature Fatigue T2 - The FVV Transfer + Networking Event | Information Sessions – Autumn 2023 N2 - The high operating temperatures of radial compressor wheels in exhaust gas turbochargers lead to a change in the original microstructure of the heat-resistant aluminum alloy EN AW-2618A (overaging). This is caused by thermal loads that are close to the age hardening temperature and can even exceed it for a short time. The aging mechanisms have been investigated together with low cycle fatigue (LCF), thermomechanical fatigue (TMF) and creep up to max. 190 °C in previous research projects. The be-havior of the alloy under high cycle fatigue (HCF) and the influence of load spectra have hardly been investigated. Since the operating temperatures of centrifugal compressors are expected to increase in the future, this research project investigated the HCF behavior at 230 °C, a test temperature significantly higher than the age hardening temperature. The objectives of the project were to establish a suitable experimental database, to understand the relevant microstructural processes, and to further develop and adapt suitable models and evaluation methods. In addition to a basic characterization of the HCF behavior in the initial condition T61, the experimental investigation program included targeted mechanical tests to isolate the influencing factors of mean stress (𝑅=−1, 𝑅=0.1), material overaging (T61, 10 h/230 °C, 1000 h/230 °C), test temperature (20 °C, 230 °C), test frequency (0.2 Hz, 20 Hz) as well as variable amplitudes. On this basis, the models and evaluation methods developed in the previous projects were adapted and further developed to reflect thermal and mechanical loads in the lifetime assessment. T2 - The FVV Transfer + Networking Event (Herbst 2023) CY - Würzburg, Germany DA - 04.10.2023 KW - Aluminum alloys KW - Fatigue KW - EN AW-2618A PY - 2023 SP - 1 EP - 30 AN - OPUS4-58562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kling e Silva, Lucas A1 - Pereira, Gabriela Ribeiro A1 - Jardim, Paula Mendes A1 - Sonntag, Nadja A1 - Skrotzki, Birgit T1 - CARACTERIZAÇÃO MAGNÉTICA DOS EFEITOS DE DEFORMAÇÃO EM AÇOS ESTRUTURAIS ATRAVÉS DA TÉCNICA BITTER MODIFICADA T2 - 72nd ABM Annual Congress N2 - The plastic deformation results in irreversible microstructure changes in the steel, which can be considered as the initial stage of the fracture process. However, detecting, monitoring and evaluating, damage states and small defects non-destructively in advance still proves challenging. It was reported in literature the phenomenon of the spontaneous emergence of weak magnetic fields in structural steels and pipelines, which originates due to heterogeneous mechanical and / or thermal stresses. This observation is not associated with induced phase transformations by deformation and appears to be a promising tool for the prior characterization of damage in ferromagnetic steels. To provide a better understanding of the physical bases of the process, the magnetic microstructure of such materials and the change of magnetic domains after undergoing plastic deformation were studied. For this purpose, a colloidal solution with paramagnetic particles in the nanometer scale (ferrofluid) was used, through the Bitter technique, in order to, not only observe a change in size of the magnetic domains of the material, but also changes in their morphology. Ferritic steels with different carbon contents (0.08%; 0.22% and 0.45%) were studied in this work. T2 - ABM Week 2017 CY - Sao Paulo, Brazil DA - 02.10.2017 KW - Magnetic domains KW - Steels KW - Ferrofluid KW - Plastic deformation PY - 2017 DO - https://doi.org/10.5151/1516-392X-30810 SN - 2594-5327 VL - 72 IS - 1 SP - 3003 EP - 3013 PB - Blucher Preceeding CY - Brasilien AN - OPUS4-48876 LA - por AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kling e Silva, Lucas A1 - Sonntag, Nadja A1 - Skrotzki, Birgit T1 - CARACTERIZAÇÃO MAGNÉTICA PRÉ E PÓS DEFORMAÇÃO DE AÇOS DE CONSTRUÇÃO NÃO LIGADOS ATRAVÉS DA TÉCNICA BITTER (FERROFLUIDO) T1 - Magnetic characterization before and after deformation of non-alloyed contruction steels using bitter technic T2 - 15th Enemet N2 - The plastic deformation results in irreversible microstructure changes in the steel, which can be considered as the initial stage of the fracture process. However, detecting, monitoring and evaluating, damage states and small defects non-destructively in advance still proves challenging. Dubov reported the phenomenon of the spontaneous emergence of weak magnetic fields in ferritic structural steel and pipelines, which originate due to heterogeneous mechanical and / or thermal stresses. This observation is not associated with induced phase transformations by deformation and appears to be a promising tool for the prior characterization of damage in ferromagnetic steels. To provide a better understanding of the physical bases of the process, the magnetic microstructure of such materials and a change of magnetic domains after undergoing plastic deformation were studied. A colloidal solution with paramagnetic particles in the nanometer range (ferrofluid), which allowed, through the Bitter technique, not only to observe a change in size of the magnetic domains of the material, but also changes in their morphology. Ferritic steels with their concentrations of carbon in its composition (0.12%; 0.17% and 0.45%) were studied in this work. T2 - 15° ENEMET - ABM Week 2015 CY - Rio de Janeiro, Brazil DA - 17.08.2015 KW - Magnetic Domains KW - Bitter Technique KW - Steels KW - Ferrofluid PY - 2015 DO - https://doi.org/10.5151/1516-392X-26931 SN - 2594-4711 VL - 15 IS - 15 SP - 2942 EP - 2950 PB - Blucher Preceedings CY - Rio de Janeiro, Brazil AN - OPUS4-48875 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grun, Benthe Birger A1 - Skrotzki, Birgit A1 - Olbricht, Jürgen ED - Christ, Hans-Jürgen T1 - Charakterisierung von Hochtemperaturwerkstoffen durch Zug- und Ermüdungsversuche an Kleinproben T1 - Characterization of high-temperature materials by tensile and fatigue tests on small specimens T2 - Tagung Werkstoffprüfung 2019 N2 - Die Verwendung von miniaturisierten Probengeometrien in der mechanischen Prüfung ermöglicht die Entnahme des Probenmaterials direkt aus kritischen Bereichen wie Fügeverbindungen und ermöglicht die Prüfung von kleinen Bauteilen wie additiv gefertigten Strukturen. In der vorliegenden Arbeit werden exemplarisch die Ergebnisse von vergleichenden Zug- und niederzyklischen Schwing-versuchen (LCF) an dem austenitischen Stahl AISI 316L und der Nickelbasislegierung IN718 vorgestellt. Die Prüfergebnisse der Kleinproben aus AISI 316L weisen die charakteristischen Eigenschaften des Werkstoffs auf, und die Analyse der Zug- und Ermüdungsdaten führt zu Werten, die den Literaturdaten weitgehend entsprechen. Der direkte Vergleich mit Standardprobendaten zeigt jedoch systematische Abweichungen bei Zugfestigkeit, Dehngrenze und Gleichmaßdehnung, die in diesem Beitrag diskutiert werden. N2 - The use of miniaturized specimen geometries in mechanical testing allows to extract speci-men material directly from critical areas such as weldments and to test small structures such as additively manufactured components. In the present paper, example results of comparative tensile and low-cyclic fatigue tests (LCF) on the austenitic steel AISI 316L and the nickel-based alloy IN718 are presented. The test results of the small specimens on AISI 316L show the characteristic properties of the material, and the analysis of the tensile and fatigue tests leads to values which largely correspond to literature data. However, the direct comparison with standard sample data shows systematic deviations in tensile strength, yield strength and uniform elongation, which are discussed in this paper. T2 - Werkstoffprüfung 2019 CY - Neu-Ulm, Germany DA - 03.12.2019 KW - Kleinprobenprüfung KW - Probengrößeneffekt KW - Low Cycle Fatigue KW - Zugversuch KW - AISI 316L KW - IN 718 PY - 2019 SP - 329 EP - 334 AN - OPUS4-50220 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - von Hartrott, P. A1 - Metzger, M. A1 - Skrotzki, Birgit T1 - Comparison of S-phase coarsening in alloy 2618A during ageing, creep, and fatigue T2 - Conference proceedings of LightMAT 2017 N2 - The coarsening of S-phase precipitates in alloy 2618A was compared for different ageing conditions (heat treatment, creep, and fatigue). T2 - LightMAT 2017 CY - Bremen, Germany DA - 08.11.2017 KW - Alloy 2618A KW - Degradation KW - Coarsening KW - S-phase KW - Dark-field transmission electron microscopy (DFTEM) PY - 2017 SP - 1 EP - 3 AN - OPUS4-42837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Hartrott, P. A1 - Rockenhäuser, Christian A1 - Schriever, Sina A1 - Skrotzki, Birgit T1 - Correlation of the precipitate size evolution and the creep rate of the aluminium alloy EN AW 2618A at 190 °C T2 - Proceedings of the International Conference on Aluminium Alloys 16 N2 - A short description of the work done on the topic "Correlation of the precipitate size evolution and the creep rate of the aluminium alloy EN AW 2618A at 190 °C" is given. T2 - International Conference on Aluminium Alloys 16 CY - Montreal, Canada DA - 17.06.2018 KW - Alloy 2618A KW - Degradation KW - Aluminium KW - Creep KW - Coarsening PY - 2018 SN - 978-1-926872-41-4 SP - 99 AN - OPUS4-45284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Olbricht, Jürgen A1 - Agudo Jácome, Leonardo A1 - Jürgens, Maria A1 - Roohbakhshan, Farshad A1 - Fedelich, Bernard A1 - Skrotzki, Birgit T1 - Cyclic loading performance and related microstructure evolution of ferritic-martensitic 9-12% Cr steels T2 - Fit for Future - Advances in Materials, Manufacturing and Assessment. Proceedings of the 44th MPA-Seminar N2 - The current competitive situation on electricity markets forces power plants into cyclic operation regimes with frequent load shifts and starts/shutdowns. In the present work, the cyclic mechanical behavior of ferritic-martensitic 9-12 % Cr steels under isothermal and thermomechanical loading was investigated for the example of grade P92 material. A continuous softening was observed under all loading conditions. The introduction of hold periods to the applied cycles reduced material lifetime, with most prominent effects at technologically relevant small strain levels. The microstructural characterization reveals a coarsening of the original “martensitic” lath-type microstructure to a structure with polygonal subgrains and reduced dislocation density. The microstructural data forms the input for a physically-based modelling approach. T2 - 44th MPA-Seminar CY - Leinfelden/Stuttgart, Germany DA - 17.10.2018 KW - Ferritic-martensitic steels KW - Cyclic loading KW - Microstructure evolution PY - 2018 SP - 259 EP - 265 AN - OPUS4-47118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - von Hartrott, P. A1 - Metzger, M. A1 - Skrotzki, Birgit T1 - Digital material representation of precipitation coarsening in alloy 2618A for the lifetime assessment of radial compressor wheels T2 - Microscopy Conference 2019 (MC2019) - Proceedings N2 - The concept of digital material representation is introduced and the aluminium alloy 2618A is discussed as an example of this concept regarding the simulation of material ageing based on nanoscaled precipitates. T2 - Microscopy Conference 2019 (MC2019) CY - Berlin, Germany DA - 01.09.2019 KW - Alloy 2618A KW - Aluminium KW - Digital material representation KW - Transmission electron microscopy KW - Material degradation PY - 2019 SP - 183 EP - 184 AN - OPUS4-48885 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Uckert, Danilo A1 - Kühn, Hans-Joachim A1 - Matzak, Kathrin A1 - Rehmer, Birgit A1 - Skrotzki, Birgit T1 - Ermüdungsverhalten des warmfesten austenitischen Gusseisens EN-GJSA-XNiSiCr35-5-2 bei hoher Temperatur T2 - Tagungsband 41. Vortragsveranstaltung Langzeitverhalten warmfester Stähle und Hochtemperaturwerkstoffe N2 - Die warmfeste austenitische Gusseisenlegierung EN-GJSA-XNiSiCr35-5-2 (häufig auch als Ni-Resist D-5S bezeichnet) wurde hinsichtlich ihres mechanischen Verhaltens bei hoher Temperatur charakterisiert. Dazu wurden (isotherme) niederzyklische (LCF-) und (nicht-isotherme) thermomechanische Ermüdungsversuche (TMF) zwischen Raumtemperatur und 900 °C durchgeführt. Diese Ergebnisse dienten (zusammen mit weiteren Versuchsdaten) der Kalibrierung werkstoffmechanischer Modelle. Bei den höchsten Prüftemperaturen wurde Schädigung in Form von Kriechen beobachtet und metallographisch dokumentiert. T2 - Langzeitverhalten warmfester Stähle und Hochtemperaturwerkstoffe CY - Dusseldorf, Germany DA - 30.11.2018 KW - Kriechen KW - LCF KW - Lebensdauer KW - Ni-Resist KW - Schädigung KW - TMF PY - 2018 SN - 978-3-00-061694-5 SP - 29 EP - 38 CY - Düsseldorf AN - OPUS4-46919 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -