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Journal of Materials Science

, Volume 26, Issue 16, pp 4527–4533 | Cite as

Dynamic observation of fracture in particulate-filled epoxy resins reinforced with rubber

  • G. Vekinis
  • P. W. R. Beaumont
  • G. Pritchard
  • R. Wainwright
Papers

Abstract

Crack propagation in epoxy resins filled with alumina trihydrate has been observed by dynamic in situ scanning electron microscopy. Double torsion specimens were fractured inside a scanning electron microscope (SEM) connected to a video recorder. Characteristic features of the crack propagation process were observed. The fracture mode was mainly intergranular at low crack velocities, (ca. 10 μm/s) with evidence of filler particle cracking (transgranular fracture) at higher velocities or after acid-washing the particles. Extensive shear yielding of the epoxy matrix occurred between closely spaced filler particles within the crack tip damage zone. Post-mortem static observations of the fracture surfaces were also carried out. The addition of rubber toughening agents modified the crack propagation process. In some cases the rubber was present as fine, evenly distributed particles while in others there were coarser precipitates and/or what appeared to be rubber-rich epoxy phases. Ligamentary bridges across crack faces in the crack wake necked to fracture at low crack velocities but failed by cavitation under rapid loading. Energy dissipation by local shear yielding of the matrix was still prominent. Vinyl terminated rubber addition induced especially widespread yielding. Out-of-SEM determinations of tensile and fracture parameters were consistent with dynamic SEM observations.

Keywords

Cavitation Fracture Mode Filler Particle Shear Yielding Transgranular Fracture 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman & Hall 1991

Authors and Affiliations

  • G. Vekinis
    • 1
  • P. W. R. Beaumont
    • 1
  • G. Pritchard
    • 2
  • R. Wainwright
    • 2
  1. 1.Department of EngineeringUniversity of CambridgeCambridgeUK
  2. 2.School of Applied ChemistryKingston PolytechnicKingston upon ThamesUK

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