Failure Mechanisms

· Temperature and stress level change the both the strain and strain rate (creep) as shown.

From: Courtney,
"Mechanical Behavior
of Materials,"
McGraw Hill (1990)

· High values of temperature or stress yield three stages of creep.
(i) Primary creep in which work hardening decreases the strain rate;
(ii) Secondary creep with work hardening and recovery processes balanced; (iii) Tertiary creep where recovery dominates and ductile fracture occurs.