CONSTITUTIVE DESCRIPTION OF HIGH-TEMPERATURE CREEP IN MECHANICALLY ALLOYED AL-C-O ALLOYS

Creep curves of four mechanically alloyed aluminum alloys were studied within the range of stresses from 20 to 180 MPa at temperatures of 62 3 and 723 K. Creep curves of pure aluminum at temperatures of 473-623 K were taken as reference material data. The curves were described by the McVetty equation. The primary and steady-state stages of creep can be interpreted as a result of changes in the internal stress followin g from competition between work hardening and recovery processes. The analysis makes it possible to divide the internal stress into two comp onents, one being due to stress fields of dislocations and the other t o the existence of dispersed particles. The latter component equals th e threshold stress in steady-state creep.