Charakterisierung von Spröd/Zäh-Übergängen in PP-Compounds mittels instrumentierter Schlagbiege- und Durchstoßversuche

Translated title of the contribution: Characterization of Brittle/Ductile Transitions in PP-Compounds using Instrumented Charpy and Puncture Tests

Dieter Huber

Research output: ThesisMaster's Thesis

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Abstract

The characterization of the impact behavior of plastics is normally carried out by Charpy tests according to ISO 179 or by puncture tests according to ISO 6603. In addition to the quantitative determination of unnotched and notched impact strength and puncture energy, the position of the brittle/ductile transition on the temperature scale is of particular interest. For this master thesis, three different types of polypropylene were used for the aforementioned tests which were operated exclusively as instrumented tests. The aim of these tests was to identify the influence of test procedure, data acquisition and data reduction method. For the Charpy impact tests as well as for the puncture tests unnotched and notched specimens were used to assess and compare the effect of notching on the brittle/ductile transition temperature in both test types. For the notched puncture test, specimens with linear or circular notches were used. In addition to the quantitative analysis of the parameters energy and deflection, the qualitative evaluation of the measured curves and the specimen failure modes according to ISO standards was used for the characterization of the brittle/ductile transition. As expected, the notched Charpy test specimens generally exhibited higher transition temperatures than the unnotched ones. The same trend was found for the notched and unnotched puncture tests, but the effect was less pronounced. Moreover, the shift of the transition temperature of notched specimens turned out to dependent on the notch design, while some notched specimens did not show any transition at all. For test specimens with a circular notch, the puncture energy above the brittle/ductile transitions were similar for two PP types, irrespective of being notched or not. When comparing the notch influence on the brittle/ductile transition determined by Charpy and puncture tests no definite correlations could be found.
Translated title of the contributionCharacterization of Brittle/Ductile Transitions in PP-Compounds using Instrumented Charpy and Puncture Tests
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Major, Zoltan, Co-Supervisor (external), External person
  • Frank, Sybille, Supervisor (external), External person
  • Lang, Reinhold, Supervisor (internal)
Award date26 Jun 2009
Publication statusPublished - 2009

Bibliographical note

embargoed until null

Keywords

  • Brittle/Ductile Transition Puncture Test Charpy Test Notches

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