EFFECT OF PRECIPITATION HARDENING ON SERRATED FLOW CHARACTERISTICS IN AN Al－Li ALLOY
(Central South University of Technology; Changsha 410083)
Abstract: The serrated flow characteristics of an 8090 type Al-Li alloy during tensile testing and the effect of age hardening on serrated flow were inverstigated.The results indicated that in the as-quenched and under-aged conditions the serrated flow occurred and in the existence of serratedflow negative strain rate sensitivity was observed.In the peak and over-aged conditions serrationswere not exhibited.In addition,the predeformation prior to aging and the increasLe in strain ratesuppressed the occurrence of serrated flow.The results are discussed in terms of the interactionsof the solute atoms, dislocations and the precipitates with the mobile dislocations.
Key words: serrated flow strain aging Al-Li alloys age hardening