Creep in Nanostructured Materials

Abstract

The creep behaviour and properties of nanostructured materials are attributed to their operating deformation mechanisms, which could be different from those in their coarse-grained counterparts. Accordingly, in this review, recent progress on the creep behaviour of nanostructured materials will be described. The results of large sets of tensile creep tests on selected more complex metallic materials are analysed for evaluating the effect of different SPD processing methods on creep resistance at high temperatures. The resultant creep characteristics are compared with those attained in unprocessed conditions of the same materials. By contrast to the creep behaviour of UFG pure metals SPD processing of more complex materials mostly exhibits no essentially improved creep resistance. Evaluated stress dependences of the creep rate and the creep life suggest that creep deformation mechanisms in UFG materials are similar to those operating in coarse-grained materials. However, creep mechanisms in SPD processed materials are not clearly resolved and this is due to complexity of phenomenon and very small number of studies that have been carried out before now.