Microstructural dependence of effective stresses and activation volumes during creep

摘要: Abstract Macroscopic measurements of internal stresses and activation volumes made by stress relaxation or reduction tests performed in the past have led to controversial interpretations about strain rate controlling mechanism during secondary creep. The fact that these macroscopic provide only average values over crystal makes it very difficult relate them microscopic activated events which dislocations overcome obstacles locally. In this work, local effective existing creep an Al Zn alloy been measured fro different conditions temperature. At same time, variation substructure parameters such as subgrain size subboundary mesh has studied. Detailed analysis dislocation emission at subboundaries appears junction recombination generally occurs glide cross-slip. A simple equation developed relating all parameters, deduced. latter appear decrease with increasing stress. are related size, confirming a under action produces controls rate.