TY - CONF A1 - Skrotzki, Birgit A1 - Kühn, Hans-Joachim ED - Grellmann, W. T1 - Kennwertermittlung aus statischen und zyklischen Versuchen bei erhöhter Temperatur unter isothermer und nicht isothermer Beanspruchung T2 - DVM-Tagung Werkstoffprüfung 2011 - Neue Entwicklungen in der Werkstoffprüfung - Herausforderungen an die Kennwertermittlung T2 - DVM-Tagung Werkstoffprüfung 2011 - Neue Entwicklungen in der Werkstoffprüfung - Herausforderungen an die Kennwertermittlung CY - Berlin, Germany DA - 2011-12-01 KW - Kennwert KW - Temperatur KW - E-Modul KW - Warmzugversuch KW - Ermüdung KW - Mechanical properties KW - Temperature KW - Young´s modulus KW - Elevated temperature tensile test KW - Fatigue PY - 2011 SN - 978-3-9814516-1-0 SN - 1861-8154 N1 - Serientitel: DVM-Bericht – Series title: DVM-Bericht IS - 643 SP - 37 EP - 44 AN - OPUS4-24969 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skrotzki, Birgit A1 - Koch, B. T1 - Microstructural characterization of the metastable Beta-titanium alloy TIMETAL LCB after fatigue loading T2 - International conference on electron nanoscopy & XXXII Annual meeting of EMSI N2 - In the present work, the titanium alloy Ti-6.8Mo-4.5Fe-1.5Al (Timetal LCB) was investigated with respect to the microstructural evolution during strain controlled fatigue loading. The alloy was developed to reduce the generally high material costs of β-alloys by substituting expensive beta stabilizers by using a standard Fe-Mo master alloy. One possible application seen in the automotive industry is the substitution os suspension structural parts currently made of steel, suc as suspension springs. These components require a high strength and fatigue resistance. T2 - International conference on electron nanoscopy & XXXII Annual meeting of EMSI CY - Hyderabad, India DA - 2011-07-06 KW - Titanium KW - Fatigue KW - Microstructure KW - Deformation mechanism PY - 2011 SP - 255 EP - 256 AN - OPUS4-24167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Bernd A1 - Skrotzki, Birgit T1 - Strain controlled fatigue testing of the metastable Beta-titanium alloy Ti-6.8Mo-4.5Fe-1.5Al (Timetal LCB) JF - Materials science and engineering A N2 - The present work covers the mechanical behaviour of Timetal LCB under fatigue loading and utilizes transmission electron microscopy (TEM) to study the associated microstructural evolution. Fatigue specimens were taken out of LCB wire made for automotive suspension spring manufacturing in a solution treated as well as an additionally aged state. Uniaxial fatigue tests were carried out in total strain control with R = 0.1. Solution treated specimens tested at 3% and 4% maximum total strain showed a saturating force response, which differed from all other total strain controlled tests, and a distinct fracture behaviour. In addition, an increase of the dynamic Young's modulus is observed under these test conditions and in this material state. These findings are interpreted as a deformation induced precipitation of nanosize α- or ω-phase. In the aged state, the α-phase carries the major part of deformation work, noticeable by distinct α-substructures in fatigued specimen states. KW - Titanium alloys KW - Fatigue KW - Transmission electron microscopy KW - Fracture PY - 2011 DO - https://doi.org/10.1016/j.msea.2011.04.031 SN - 0921-5093 SN - 1873-4936 VL - 528 IS - 18 SP - 5999 EP - 6005 PB - Elsevier CY - Amsterdam AN - OPUS4-23731 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rehmer, Birgit A1 - Skrotzki, Birgit A1 - Glaubitz, Steffen T1 - Influence of casting skin on fatigue lifetime of ferritic ductile cast iron JF - Materials Testing N2 - The fatigue behaviour of cast iron is usually investigated on machined specimens. Components of cast iron, however, have a casting skin; therefore the investigation of the influence of the casting skin on the lifetime is of interest. To study this influence isothermal fatigue tests were carried out on heat-resisting spheroidal graphite cast iron EN GJS SiMo 4.05 in 4–point-bending set-up at 400 °C. Specimens with and without casting skin were investigated comparatively. The number of cycles to failure was significantly lower for specimens with casting skin. Metallographic investigations underline the reduction of lifetime caused by casting skin. KW - Cast iron KW - Casting skin KW - Fatigue KW - Lifetime PY - 2017 SN - 0025-5300 VL - 59 IS - 1 SP - 5 EP - 10 PB - Carl Hanser Verlag CY - München AN - OPUS4-38929 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 - JOUR A1 - Han, Ying A1 - Kruse, Julius A1 - Rosalie, Julian A1 - Radners, J. A1 - von Hartrott, P. A1 - Skrotzki, Birgit T1 - Influence of mean stress and overaging on fatigue life of aluminum alloy EN AW-2618A JF - Materials Science & Engineering A N2 - Fatigue tests were performed on the forged aluminum alloy EN AW-2618A in the T61 state. Different stress ratios (R = -1, R = 0.1) were selected to study the influence of mean stress on fatigue life. Two overaged states (10 h/230 ◦C, 1000 h/230 ◦C) were also tested to investigate the influence of overaging on fatigue life. Transmission electron microscopy (TEM) was used to characterize the precipitates (S-phase), which are mainly responsible for the strength of the alloy. A fractographic analysis was also performed to determine the failure mode. Overaging reduces the fatigue life compared to the T61 state. The longer the aging time, the lower the fatigue resistance. The reason is the decrease in (yield) strength, which correlates with the radius of the S-phase: the precipitate radius increases by a factor of approximately two for the overaged states compared to the initial state. The analysis of the fracture surfaces showed crack initiation occurs predominantly on the outer surface and is associated with the primary phases. KW - Aluminum alloys KW - Aging KW - Fatigue KW - Microstructure KW - Electron microscopy KW - S-Phase PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-583708 DO - https://doi.org/10.1016/j.msea.2023.145660 SN - 0921-5093 VL - 886 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-58370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hilgenberg, Kai A1 - Daum, Werner A1 - Maierhofer, Christiane A1 - Altenburg, Simon A1 - Bruno, Giovanni A1 - Heckel, Thomas A1 - Skrotzki, Birgit A1 - Zerbst, Uwe A1 - Kranzmann, Axel A1 - Bettge, Dirk A1 - Sommer, Konstantin A1 - Seeger, Stefan A1 - Nitsche, Michael A1 - Günster, Jens A1 - Evans, Alexander T1 - Additive manufacturing at the BAM: We focus on Safety JF - Advanced Materials and Processes N2 - In Germany, the Federal Institute for Materials Research and Testing (BAM) is addressing challenges in the implementation of additive manufacturing on the industrial landscape for safety-critical applications. KW - Process development KW - Additive Manufacturing KW - In-situ Process Monitoring KW - Non-destructive Materials KW - Characterisation KW - Safety KW - Fatigue KW - Environment KW - Standardisation PY - 2019 UR - https://static.asminternational.org/amp/201910/22/ SN - 0882-7958 VL - 177 IS - 7 SP - 22 EP - 26 PB - ASM International CY - Materials Park, OH, USA AN - OPUS4-49780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -