PHASE-COMPOSITION AND JERKY FLOW IN AL-LI-MG-CU ALLOY

A detailed study of the decomposition process of supersaturated Al-Li- Mg-Cu solid solution was performed during isochronal annealing by mean s oi electrical resistometry and EM. The influence of the phase compos ition on jerky flow was studied and the conditions for the occurrence of this effect were tested. The concentration of free Li atoms in supe rsaturated solid solution was shown to have a significant influence on the critical strain for the onset of jerky flow. The temperature limi t for the vanishing of jerky flow was also found. Results are compared with a recent model by Kubin and Estrin and Brechet and Estrin.