A Study on Hot Tearing in Direct Chill Casting of Al-Mn-Mg Alloys Using a Multi-scale Approach
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Overview
Overview
abstract
A multi-scale approach for simulating hot tearing during the DC casting of aluminum alloys
is presented. The novelty of this approach lies in the combination of a macro-scale finite element
simulation of the DC casting process with direct prediction of hot tears via a meso-scale multi-physics granular model. This approach is capable of simulating hot tearing initiation, growth,
and propagation within a representative volume element of the mushy zone. The change of cooling conditions experienced by the DC cast billet as a result of variations in casting speed as well
as non-uniformity of heat extraction from different locations of the billet affect the deformation
state, cooling rate, and thermal gradient, which further influence the strain rate, grain size, permeability, and feeding coefficient. Considering all the mentioned parameters, the multi-scale
approach emphasizes the fact that hot tearing is a phenomenon resulting from the combination
of the tensile deformation and restricted feeding of the mushy zone. The developed hot tearing
formation maps identify the locations where hot tearing will occur as predicted by the multi-scale
approach for two alloys - AA5182 and AA3104 - thus demonstrating the approach’s sensitivity
to both processing parameters and alloy composition.
