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Large plastic stability in magnesium alloys: crystalline vs. amorphous alloys
Author(s) -
Boissière R.,
Puech S.,
Blandin J.J.
Publication year - 2008
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.200800290
Subject(s) - superplasticity , materials science , amorphous solid , deformation (meteorology) , magnesium , fracture (geology) , metallurgy , newtonian fluid , strain rate , stability (learning theory) , plasticity , magnesium alloy , composite material , thermodynamics , microstructure , crystallography , chemistry , physics , machine learning , computer science
Except if strain induces damage, the plastic stability can be roughly estimated thanks to the value of the strain rate sensitivity parameter m . In conventional magnesium alloys, moderate values of m (typically close to 0.3) can be frequently obtained during high temperature deformation. Such values allow reaching significant elongations to fracture. For alloys displaying fine grains, superplastic properties associated with values of m of about 0.5 or more are achievable leading to large elongations to fracture in optimized conditions for which damage processes remain limited. Quite recently, amorphous magnesium alloys have been produced in bulk conditions. In appropriate conditions of deformation, these alloys display Newtonian behaviour (i.e. m = 1). With such rheologies, the plastic stability is expected to be maximal. In this presentation, features in relation with high temperature deformation of amorphous and crystalline magnesium alloys will be compared and apparent similitudes and differences will be discussed.