TY - CHAP A1 - Zerbst, Uwe A1 - Madia, Mauro ED - Yadroitsev, I. ED - Yadroitsava, I. ED - Du Plessies, A. ED - McDonald, E. T1 - Structural integrity II: fatigue properties N2 - If a component is cyclically loaded, its load carrying capacity is considerably lower than in the monotonic loading case. This general observation applies in particular to L-PBF parts. The causes of this are mainly material defects such as pores and unwelded regions (Chapter 8) and a pronounced surface roughness in the as-built condition (Chapter 9). In addition, effects due to the anisotropy of the microstructure (Chapter 6) and a complex residual stress pattern (Chapter 7) play an important role. A consequence is that common strategies of fatigue assessment cannot be transferred to L-PBF applications without modifications. Due to the inhomogeneity of the material, the determination of representative material properties and the transfer to the component is a problem, and this is also the case with regard to the consideration of defects, surface roughness and residual stresses. The chapter gives a brief introduction to these problem areas. KW - Fatigue crack propagation stagesdefects KW - Fatigue strength KW - Fatigue life KW - Fracture mechanics PY - 2021 SN - 978-0-12-824090-8 U6 - https://doi.org/10.1016/B978-0-12-824090-8.00015-9 SP - 377 EP - 394 PB - Elsevier Inc. CY - Amsterdam ET - 1 AN - OPUS4-52854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Eissel, A. A1 - Engelking, Lorenz A1 - Treutler, K. A1 - Schroepfer, Dirk A1 - Wesling, V. A1 - Kannengießer, Thomas ED - da Silva, L. F. M. ED - Martins, P. A. F. ED - Reisgen, U. T1 - Nickel-Iron-Alloy Modification to Enhance Additively Welded Microstructure for Subsequent Milling N2 - The aerospace industry uses nickel–iron alloys, e.g., FeNi36, to create moulding tools for composite materials, since these alloys have a low coefficient of thermal expansion. Nickel–iron alloys are hard-to-cut materials. The moulding tools are large in size and involve complex structures, making them cost-intensive and difficult to manufacture. Thus, the focus is set on additive manufacturing, which can additionally enable the repair of components in order to eliminate local defects. However, the process usually results in a heterogeneous microstructure and anisotropic mechanical properties. As there is a high demand for a precise and exact fit of the precision moulds and the surface quality, the welded components must be subsequently machined. Additionally, inhomogeneous microstructure may lead to unstable cutting forces and conditions. Consequently, a modification of the microstructure morphology is achieved through specific alloy modifications in order to stabilise and improve the subsequent machining process. Therefore, titanium and zirconium are chosen as modification elements with a maximum 1% weight percent and are added to nickel–iron alloy powder. The elements are alloyed, and build-up welded by plasma-transferred-arcwelding. The resulting microstructure morphology of the welded wall structure and the machining properties are then determined. It can be shown that titanium has a significant effect on the structural morphology of the welded layers, as well as on the machining. KW - Alloy modification KW - Alloy 36 KW - Plasma-transferred arc welding KW - Ultrasonic-assisted milling KW - Surface integrity PY - 2022 SN - 978-3-030-95463-5 U6 - https://doi.org/10.1007/978-3-030-95463-5_6 SP - 85 EP - 99 PB - Springer CY - Cham AN - OPUS4-55484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Böllinghaus, Thomas A1 - Rhode, Michael A1 - Falkenreck, T. ED - Bender, B. ED - Göhlich, D. T1 - Korrosion und Korrosionsschutz N2 - Das Kapitel beginnt mit einer kurzen Einführung über die Korrosion (Wechselwirkung zwischen einem Metall, einer korrosiven Umgebung und der der jeweiligen Konstruktion). Im zweiten Abschnitt werden die wichtigsten Formen der wässrigen elektrochemischen Korrosion (Flächenkorrosion, galvanische, selektive und interkristalline Korrosion sowie Loch- und Spaltkorrosion) betrachtet. Darüber hinaus wird die elektrochemische Korrosion unter mechanischer Belastung betrachtet (Spannungsrisskorrosion, wasserstoffunterstützte Rissbildung, Korrosionsermüdung), sowie Sonderformen der Korrosion (Erosion, Fretting und mikrobiologisch induzierte Korrosion). Der dritte Abschnitt befasst sich mit der chemischen und Hochtemperaturkorrosion (Oxidation, Aufkohlung, Hochtemperatur-Wasserstoffangriff, Aufschwefelung, Nitrierung, Halogenierung). Zusätzlich enthält das Kapitel Maßnahmen zur Vermeidung der Korrosion. KW - Korrosion KW - Korrosionsschutz KW - Spannungsrisskorrosion KW - Wasserstoff KW - Loch- u. Spaltkorrosion PY - 2021 SN - 978-3-662-59710-1 U6 - https://doi.org/10.1007/978-3-662-59711-8_34 VL - 1 SP - 691 EP - 725 PB - Springer-Verlag GmbH, ein Teil von Springer Nature CY - Berlin ET - 26 AN - OPUS4-52156 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Böllinghaus, Thomas A1 - Rhode, Michael A1 - Falkenreck, T. ED - Grote, K.-H. ED - Hefazi, H. T1 - 6. Corrosion and Corrosion Resistance N2 - The chapter starts with a brief introduction about corrosion, which is defined as the interdependency between a metal, a corrosive environment, and the respective component design. The second section introduces the most important forms of aqueous electrochemical corrosion (uniform corrosion, galvanic corrosion, selective and intergranular corrosion, and finally pitting and crevice corrosion in the case of passive layer forming metals). In addition, electrochemical corrosion under applied mechanical load is introduced (stress corrosion cracking, hydrogen-assisted cracking, corrosion fatigue), as well as special forms of corrosion (erosion, fretting, and microbiologically induced corrosion). The third section of this chapter introduces (mostly dry) chemical corrosion and high-temperature corrosion (oxidation, carburization, high-temperature hydrogen attack, sulfurization, nitriding, halogenation). As in the case of electrochemical corrosion, chemical corrosion can also be superimposed by mechanical loads. Finally, general facts on the testing of corrosion are introduced. KW - Corrosion KW - Corrosion testing KW - Handbook KW - Electrochemical corrosion KW - Chemical corrosion PY - 2021 SN - 978-3-030-47035-7 U6 - https://doi.org/10.1007/978-3-030-47035-7_6 VL - 2021 SP - 185 EP - 213 PB - Springer Nature Switzerland AG CY - Cham (CH) ET - 2nd Edition AN - OPUS4-52423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Friedrich, K. A1 - Theiler, Geraldine A1 - Klein, P. ED - Sinha, S. K. T1 - Chapter 9: Polymer composites for tribological applications in a range between liquid helium and room temperature N2 - This chapter deals with the development of polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE)-based composites, optimized for low friction and low wear performance under extreme environments. It is demonstrated that the incorporation of a harder polymer component into PTFE (such as PEEK particles), a short fiber reinforcement (e.g. carbon fibers (CFs)) and internal lubricants (e.g. PTFE particles) helps to reduce the friction and to improve the wear resistance over a very wide temperature range. KW - Polymer composites KW - Friction KW - Wear KW - Cryogenic temperature PY - 2018 SN - 978-981-3227-78-1 SN - 978-981-3227-80-4 SP - 307 EP - 343 PB - World Scientific Publishing Co. Pte. Ltd. AN - OPUS4-46321 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -