To clarify the relationship between the decompression failure behaviours of EPDM and the nature of their reinforcement fillers, EPDM composites were exposed to hydrogen gas at 30 °C and up to 10 MPa. Optical microscopic studies of the interiors of composites showed that cracks initiated as a result of stress concentrations from micrometre-sized bubbles formed by supersaturated hydrogen after decompression. The critical pressure (pFat which no cracks initiated after decompression was determined. Each bubble was regarded as a disc-like cavity with an internal pressure, and its tearing energy (Twas calculated by the finite-element method. The critical inner pressure (II Fwas then calculated on the basis of the criterion that T ≫; Ts,th (the threshold tearing energy for a static crack. The critical hydrogen pressures of unfilled and silica-filled EPDM could be successfully estimated because pF ∼ IIF. However, for the carbon black-filled composite (CBP the value of IIF was about twice that of pF. It is considered that the internal pressure of bubbles (IIbecame higher than the applied pressure of hydrogen (pin terms of absorbed hydrogen on carbon black in CBP, unlike unfilled or silica-filled composites.
|Publication status||Published - Dec 1 2010|
|Event||18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale, ECF 2010 - Dresden, Germany|
Duration: Aug 30 2010 → Sep 3 2010
|Other||18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale, ECF 2010|
|Period||8/30/10 → 9/3/10|
All Science Journal Classification (ASJC) codes
- Mechanics of Materials