Pipe-Diffusion-Controlled Creep Under Constant Structure Of An Aluminum-Alloy

An alternative interpretation of the creep behaviour at intermediate homologous temperatures of an Al alloy containing fine intermetallic particles is presented. It is suggested that the creep behaviour of this alloy is the result of dislocation motion under constant-structure conditions (n = 8) which takes into account a threshold stress. An activation energy for creep of 85 kJ mol-1 is obtained which is in good agreement with the activation energy for pipe diffusion in Al. It is proposed that pipe diffusion is the rate-controlling process during creep.