The reported research establishes a semi-analytical computational predictive model of fractal microstructure
in ball-milled metal foils and powder particulates, with emphasis on its transformation mechanics
via an energy-based approach. The evolving structure is composed of reconfigurable warped
ellipsoid material domains, subjected to collisions with the ball milling impactors following Brownian
motion energetics. In the first step of the model, impacts are assumed to generate ideal Hertzian elastic
stress fields, with associated bulk deformations quantified as per Castigliano's strain energy methods. In
the second stage of the model, elastic energies are recast to produce frictional slip and plastic yield, thus
resulting in surface micro-joints. Only two parameters of the model necessitate experimental calibration,
performed by comparison of joint energy with laboratory tensile measurements on ball-milled multilayer
Al-Ni foils. Model predictions of evolving internal microstructure are validated against SEM micrographs
of Al-Ni powder particulate samples for different ball milling durations. Results demonstrate
the capability of the model to accurately capture relevant fractal measures of the microstructure of ballmilled
powders.