"Measurement and Modeling of Mushy Zone Permeability in Metallic Alloy Castings" 

Logan Mick, MSE PhD Candidate 

Advisor: Professor Matthew Krane

ABSTRACT

During solidification, permeability controls the resistance to fluid motion through the developing interdendritic network, which contributes to the development of macrosegregation, shrinkage porosity, and hot tears. As a result, casting simulations require an accurate characterization of permeability within the mushy zone to predict solidification behavior. This paper reviews permeability models, stressing the measurement and determination of mushy-zone permeability in metal alloy castings. The use of permeability models is first examined to establish how interdendritic geometry influences resistance to fluid flow during solidification and the conditions under which different flow models are applicable. The study then compares experimental, numerical, and physical analog approaches for determining permeability, focusing on their methodologies, ranges of applicability, and the challenges presented by complex dendritic structure. Particular attention is given to physical analog modeling as an additional approach to address limitations associated with experimental and numerical methods. An area of interest is identified in low-fraction solid permeability, demonstrating the need for improved permeability modeling that encompasses a broader range of mushy-zone conditions.