High temperature properties of dispersion strengthened materials produced by mechanical alloying : current theoretical understanding and some practical implications

Abstract

The typical effects of dispersoid particles and grain structure on creep of dispersion-strengthened materials are described. The current theoretical understanding of dislocation processes in these materials is reviewd extensively. It is argued that recent models based on dislocation detachment from dispersoid particles can have important practical implications for future alloy design and optimization. For creep data extrapolation, threshold stress concepts should be used with caution. Achievements and shortcomings of current models for grain boundary effects are also discussed. It is concluded that the creep behaviour of polycrystalline dispersion-strengthened materials is not fully understood and necessitates further work.