Deformation by grain boundary sliding and slip creep versus diffusional creep

摘要: A review is presented of the debates between present authors and other investigators regarding possible role diffusional creep in plastic flow polycrystalline metals at low stresses. These are recorded eleven papers over past seventeen years. ln these it has been shown that rates materials so-called "diffusional region" almost always higher than those predicted by theory. Additionally, predictions grain size effects stress exponents from theory often not found experimental data. Finally, denuded zones have universally considered to be direct evidence for creep; but, reported literature only under conditions where a high exponent observed. Also, locations do match predicted. Alternative mechanisms described which diffusion-controlled dislocation and/or boundary sliding dominant deformation processes low-stress creep. It proposed formed stress-directed migration with precipitates dissolving moving boundaries. The above observations led us conclusion andmore » slip fact principal regions".« less