INFLUENCE OF AGING ON SERRATED FLOW OF ALUMINUM ALLOY LC9

The serratedflow of alloy LC9 with different regimes of heat treatment has been investigatedat constant rate of stretching.The critieal strain ε_c at the starting of serrated flow increaseswith the extension of aging.The activation energy of the process is 0.63 e V which is consistentwith the diffusion activation energy of vacancies in A1.The ε_c decreases while the strain rate εincreases,i.e.,with negative strain rate relation.This relation is contrary to that of the an-nealed samples.It shows that the serrated 17ow of annealed sample is controlled bydeformation vaeancies,and that of aged sample is controlled by quenching vacancies.The den-sity and shape of the serration are changed by aging.The mechanism of the above mentionedresults is discussed.