TY - JOUR A1 - Zerbst, Uwe A1 - Klinger, Christian T1 - Material defects as cause for the fatigue failure of metallic components N2 - The paper provides an overview on material defects which may serve as fatigue crack initiation sites and can cause final fatigue failure of a component. These comprise nonmetallic inclusions in Steel and aluminum alloys, cavities such as pores, micro-shrinkages and un-welded regions in cast, sinter and additively manufactured alloys, graphite nodules, shrinkages and other items in modular cast iron, regions of defective microstructure, microcracks and secondary notches such as undercuts and surface roughness. Besides their origin, the effect and mechanisms on fatigue crack initiation and propagation are discussed. The considerations are proceeded and accompanied by a Brief discussion of some Basic aspects such as the stages of crack propagation along their length scale, the overcoming of crack arrest and the question when a secondary notch can be treated as a crack. KW - Material defects KW - Fatigue strength and life KW - Non-metallic inclusions KW - Pores KW - Shrinkages KW - Graphite modules KW - Surface roughness PY - 2019 DO - https://doi.org/10.1016/j.ijfatigue.2019.06.024 SN - 0142-1123 SN - 1879-3452 VL - 127 SP - 312 EP - 323 PB - Elsevier AN - OPUS4-49127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Klinger, Christian A1 - Clegg, R. T1 - Fracture mechanics as a tool in failure analysis - Prospects and limitations N2 - Although fatigue crack propagation and fracture cause a large part of failure events in industrial practice, fracture mechanics in failure analysis seems to be still a side issue. Starting from an introduction into important basic questions of failure analysis and fracture mechanics, the authors specify what kind of questions in failure analysis can be effectively solved by fracture mechanics (and which can't). They illustrate their discussion with a number of 13 case studies from the literature. Much more pronounced than in the design stage the benefit of fracture mechanics in failure analysis depends on its accuracy. This is limited by both, intrinsic factors of the method and the availability and quality of the input information. The authors discuss the various aspects and provide the reader with some background information which, as they believe, will be helpful for better understanding the prospects and limitations of fracture mechanics in failure analysis and the conditions of its application. KW - Failure analysis KW - Fracture mechanics KW - Fatigue KW - Root cause KW - Accompanying measures PY - 2015 DO - https://doi.org/10.1016/j.engfailanal.2015.07.001 SN - 1350-6307 SN - 1873-1961 VL - 55 SP - 376 EP - 410 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-33839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klinger, Christian A1 - Zunkel, Astrid T1 - Folgeschäden durch Versagen von Gummi-Metall-Verbunden T2 - 41. Jahrestagung "Schadensanalyse", VDI-Wissensforum CY - Würzburg DA - 2015-10-01 PY - 2015 AN - OPUS4-34446 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tiebe, Carlo A1 - Zunkel, Astrid A1 - Klein, Ulrich A1 - Schlischka, Jörg A1 - Klinger, Christian T1 - Materialuntersuchungen zur Schadensanalyse an einem explodierten Umlaufkühler N2 - Ein Durchlaufkühler ist im Betrieb explodiert. Die zerborstenen Gehäuseteile aus Kunststoff führten zu einem Austreten der Kühlflüssigkeit am Betriebsort sowie zu einem Personenschaden mit Knalltrauma. Bei Funktionsprüfungen am beschädigten Gerät traten unerwartet, aber reproduzierbar Knalleffekte auf der Kupfer-Kühlschlange auf. Ein möglicher Mechanismus konnte im Labor durch Synthese von Kupferazid auf Kupferproben und Auslösung vergleichbarer Knalleffekte nachgestellt werden. Damit ist die Plausibilität des beschriebenen Schadensereignisses mit diesem oder einem ähnlich reagierenden Stoff belegt. Ein eindeutiger Nachweis darüber, dass beim aufgetretenen Schadensfall dieselbe chemische Reaktion stattgefunden hat ist nicht möglich, da die Belag-Überreste aus dem explodierten Kühlgerät für eine Analyse nicht mehr in ausreichender Menge verfügbar waren. T2 - Erfahrungsaustausch für Sachverständige in der Anlagenüberwachung der Industrie (ESA 2021) CY - Online meeting DA - 20.04.2021 KW - Umlaufkühler KW - Schadensanalyse KW - Materialuntersuchungen KW - Gutachten KW - Kupferazid PY - 2021 AN - OPUS4-52484 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klinger, Christian A1 - Le, Hoa-Quynh T1 - Systematische Schadensanalyse: Vergleich und Anwendung von Richtlinien und Prozeduren N2 - Recherche verschiedener jeweils nationaler/internationaler Regelwerke und Prozeduren für die Systematische Schadensanalyse • Literaturrecherche zu Methoden der systematischen interdisziplinären Schadensanalyse • Vergleich der Regelwerke VDI 3822, ASTM, ASM sowie der Methoden • Anwendung der Regelwerke/Prozeduren und Methoden am Beispiel T2 - 46. VDI Jahrestagung: Schadensanalyse in der Energietechnik CY - Online meeting DA - 06.10.2020 KW - Regelwerke KW - Systematische Schadensanalysen, Prozeduren PY - 2020 AN - OPUS4-51401 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klinger, Christian A1 - Bettge, Dirk A1 - Ell, Matthias T1 - Failure analysis on medical implants N2 - The application of implants e.g. for osteosynthesis or substitution of worn out joints is common practice since decades. Successes in surgery and orthopedics are highly dependent on the use of artificial parts for implanting into the human body. Over the years the number of surgical procedures and the number of different implants were growing rapidly. Implants, however, are exposed to complex mechanical, corrosive and tribological loads along with restriction in geometric dimension. While being essentially successful, the sheer number of cases leads to a rising number of implant failures. Such failures are painful for the affected patients and are very costly. The failure cases presented in this paper occurred from 1981 to 2016. The predominant failure mechanism of all kinds of implants is fatigue fracture. Fatigue cracks are initiated due to a whole bunch of reasons: Material defects and fabrication defects are rare events. The main factors are cyclic overload due to improper fitting with delayed bone healing, corrosion and unauthorized modification of the implant during surgery T2 - Int. Conf. on Engineering Failure Analysis 2018 CY - Budapest, Hungary DA - 08.07.2018 KW - Implant failures KW - Complex loading KW - Fatigue fracture PY - 2018 AN - OPUS4-50198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kinder, Joachim A1 - Klinger, Christian A1 - Österle, Werner A1 - Klingbeil, Dietmar ED - Portella, Pedro Dolabella T1 - Mechanisch induzierte Zwillingsbildung in Blechen aus Baustahl T2 - 35. Metallographie-Tagung CY - Neu-Ulm, Deutschland DA - 2001-09-19 PY - 2002 SN - 3-88355-303-4 SN - 0343-3579 SP - 47 EP - 52 PB - Werkstoff-Informationsges. CY - Frankfurt AN - OPUS4-1364 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Portella, Pedro Dolabella A1 - Bettge, Dirk A1 - Klinger, Christian A1 - Baer, Wolfram T1 - Über das Versagen von Strommasten im Münsterland (Nov. 2005) - der Beitrag der Metallographie und der Fraktographie T2 - 43. Metallographie-Tagung CY - Aachen, Deutschland DA - 2009-09-16 PY - 2009 SN - 978-3-88355-376-4 VL - 41 SP - 21 EP - 30 PB - Werkstoff-Informationsges. CY - Frankfurt/M. AN - OPUS4-20061 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Klinger, Christian A1 - Bettge, Dirk A1 - Murakami, Y. T1 - Defects as a root cause of fatigue failure of metallic components. III: Cavities, dents, corrosion pits, scratches N2 - This third part of the review on defects as root cause of fatigue failure addresses cavities (pores, micro-shrinkages, unmelted regions), defective microstructures and microcracks as material defects and defects due to local damage during manufacturing, service and maintenance such as dents, scratches and localized corrosion. In addition, damage due to contact fatigue and the effect of surface roughness are discussed in the context of fatigue failure. Also addressed is the competition between different kinds of defects in controlling the initiation and early growth of fatigue cracks. KW - Pores KW - Micro-shrinkages KW - Impact damage KW - Contact fatigue KW - Corrosion pits KW - Scratches PY - 2019 DO - https://doi.org/10.1016/j.engfailanal.2019.01.034 SN - 1350-6307 VL - 97 SP - 759 EP - 776 PB - Pergamon-Elsevier Science Ltd CY - Oxford, England AN - OPUS4-47373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Klinger, Christian A1 - Bettge, Dirk A1 - Murakami, Y. T1 - Defects as a root cause of fatigue failure of metallic components. I: Basic aspects N2 - According to the definition of the ASM handbook [1,3], a defect is "an imperfection. that can be shown to cause failure by a quantitative analysis and that would not have occurred in the absence of the imperfection". The topic of the present three-part review is a discussion of defects which can cause failure in cyclically loaded structures. The features discussed comprise material defects such as non-metallic inclusions, pores or micro-shrinkages, etc. and geometric defects such as surface roughness and secondary notches which have their origin in manufacturing, and defects such as surface damage due to scratches, impact events or contact fatigue as well as corrosion pits which arise in service. In this first part, the discussion is prefaced by an introduction to basic aspects which are essential for a deeper understanding of the characteristics and mechanisms how the defects influence fatigue crack initiation and propagation. These include the life cycle of a fatigue crack from initiation up to fracture, crack arrest, multiple crack initiation and coalescence, and the material and geometrical properties affecting these. KW - Defects KW - Fatigue crack propagation stages KW - Crack arrest KW - Multiple cracks PY - 2019 DO - https://doi.org/10.1016/j.engfailanal.2019.01.055 SN - 1350-6307 VL - 97 SP - 777 EP - 792 PB - Pergamon-Elsevier Science Ltd CY - Oxford, England AN - OPUS4-47372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -