The mechanics of shear localization

The stability and resistance to premature crystallization during the solidification of modern BMGs results from a high degree of short-to-medium-range order of atomic packing that reduces the density defect of such glasses to a minimum at 

The mechanics of localized vs. homogeneous shear in metallic glasses was considered first by Spaepen (1977) and later, in more detail, by Argon (1979), who developed a perturbation model of shear localization in the context of flow by repeated STs. A more formal model was presented later by Steif et al. (1982). Similar flow-dilatancy-based models had actually been considered much earlier, independently, for flow of cohensionless media, such as sand and soils (for an overview of these see Anand and Gu (2000)). 

At a time t = 0 the shear-strain rate in a fraction/of the flowing matrix that is to become a band is suddenly increased, say, by a factor of 1.01 relative to that in the remaining matrix eomponent (1 —/), with the average applied shear strain rate being held eonstant. The perturbation solution shown in Fig. 7.23 then shows that the flow, first slowly, but then very rapidly, bifurcates, with all the shear-strain rate concentrating rapidly into the band and that in the (1 /) portion of the 

3 Temperature rises associated with shear locaiization 

For the first estimate of transient heat outflow we use the well-known planar-heat-source solution (Carslaw and Jaeger (1959) see also Lewandowski and Greer (2006)) 

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