The Portevin-Le Chatelier effect in an Al-Mg-Si alloy

摘要: Abstract The nature of the Portevin-Le Chatelier effect in an Al-Mg-Si alloy was investigated. At high strain rates, e > 10−3 min−1, and room temperature, periodic locking form serrated flow observed, which resulted from repeated Luder's band initiation propagation along specimen gauge length. Each found to initiate same region propagate length direction. Measurements strain, eL, indicated that eL proportional total independent rate. Both stress were observed increase resulting gradient increased linearly with strain. temperature rate dependence critical for flow, ec, yielded activation energy 0.64 eV a exponent 1.6 Ham-Jaffrey equation. low rates unlocking serrations characterized by negative ec.