Participation of non-compact dislocation glide in creep of copper at high temperatures

A possible participation of dislocation glide in non-compact crystal planes of copper in the high temperature creep process is assessed by means of values of activation energy. The activation energy of creep was determined alternatively from conventional data analysis, from the concept of effective and internal stresses applied to steady-state creep, and from constant-structure creep data. The results are discussed and compared with activation enthalpies of the {001} and {110} glide calculated from the kink-pair model. The calculated values are higher than the activation enthalpy of lattice diffusion. However, the activation energy of creep, which is lower than the value for lattice self-diffusion indicates rather a participation of a process with a lower activation energy than of the relatively difficult non-compact glide.