Axial fatigue behaviour of polyamide-6 and polyamide-6 nanocomposites at room temperature

Design against fatigue requires thorough understanding of the underlying fatigue mechanisms and factors influencing them. The objective of the present work is to study the effect of nanoclay addition on the temperature rise and modulus drop during cyclic loading in polyamide-6 and polyamide-6 base nanocomposite. Isocyclic stress strain curves were used to understand the deformation characteristics of test materials. Polyamide-6 samples exhibited necking and continuous temperature rise until fracture at high stress levels investigated. Addition of nanoclay improved the modulus retention compared to pristine polymers. Nanocomposite samples sustained more than 10(5) cycles at all stress levels investigated. The performance improvement due to the addition of nanoclay is attributed to decrease in the cyclic strain amplitude at a given stress level which results in reduced hysteresis heating compared to polyamide-6. (C) 2008 Elsevier Ltd. All rights reserved.