Premium
Schädigung und Bruch in superplastischen Legierungen – Stand der Technik
Author(s) -
Blandin J. J.
Publication year - 2012
Publication title -
materialwissenschaft und werkstofftechnik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.285
H-Index - 38
eISSN - 1521-4052
pISSN - 0933-5137
DOI - 10.1002/mawe.201200034
Subject(s) - superplasticity , nucleation , materials science , cavitation , grain boundary sliding , coalescence (physics) , metallurgy , grain boundary , microstructure , deformation (meteorology) , grain size , severe plastic deformation , flow stress , deformation mechanism , composite material , mechanics , thermodynamics , physics , astrobiology
Many superplastic alloys are sensitive to strain induced cavitation. A specificity of damage in superplastic conditions comes from the importance of grain boundary sliding (GBS) which induces generally a significant role of cavity coalescence compared to the conventional steps of nucleation and cavity growth. In terms of cavity morphologies, the GBS contribution promotes the development of cavities with particularly complex shapes. A way to limit damage sensitivity can be to reduce the grain size in the superplastic alloy since it is expected to decrease the associated flow stress and consequently the cavity nucleation rate during deformation. Nevertheless, for ultra fine grained microstructures (like those obtained after severe plastic deformation techniques), superplastic properties can frequently be obtained at lower temperatures than for more conventional microstructures. In such cases, the effect on cavitation may be not straightforward and may depend on applied conditions. The aim of this presentation is to give a brief review of the state of art concerning recent studies of damage in superplastic alloys and to discuss about the benefits and/or drawbacks of grain refining on the associated damage mechanisms.