Abstract
In this paper, the creep behavior of molybdenum disulphide (MoS2) filled polyamide 66 composite was investigated through sharp indentation at room temperature. Two types of indentation creep test, the 3-step indentation test, and the 5-step indentation test were considered in order to explore whether the measured creep response is mainly viscoelastic or includes a significant contribution from the plastic deformation developed during the loading phase. The experimental indentation creep data were analyzed within an analytical framework based on the hereditary integral operator for the ramp creep and a viscoelastic–plastic (VEP) model in order to determine the indentation creep compliance function including the short- and long-time modulus. The equivalent shear modulus calculated from the creep compliance function was compared to the indentation plane strain modulus derived from the initial slope of the unloading curve in order to investigate the validity of the Oliver and Pharr method.
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Acknowledgements
This work was supported by Executive Agency for Higher Education, Research, Development and Innovation Funding (CNCSIS-UEFISCDI), Project number PNII–IDEI 788/2008. In addition, the authors are grateful to Loredana Santo from Tor Vergata University of Rome (Italy), who kindly provided access to the testing equipment.
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Stan, F., Fetecau, C. Characterization of viscoelastic properties of molybdenum disulphide filled polyamide by indentation. Mech Time-Depend Mater 17, 205–221 (2013). https://doi.org/10.1007/s11043-012-9198-5
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DOI: https://doi.org/10.1007/s11043-012-9198-5