The nucleation and growth kinetics of equiaxed eutectic grains in hypoeutectic Al-Cu alloys has been investigated numerically and experimentally. Three-dimensional geometries of eutectic/ primary phases obtained by X-ray microtomography (XMT) have been used to generate computational domains for use with a eutectic transformation model. The samples for XMT analysis were extracted from a series of small-scale castings of Al-20 wt pct Cu solidified with different cooling rates to obtain a variety of microstructures. The stochastic nucleation technique has been coupled with a deterministic cellular automaton (CA) model to simulate the nucleation and growth of eutectic grains within the interdendritic network characterized by the XMT analysis. An inverse analysis approach has been employed to quantify the deterministic nucleation and growth relationships in the eutectic solidification model. Metallographic measurements of eutectic size and density made on cast samples solidified with a variety of cooling rates and quenched at different times after the start of the eutectic transformation were used in the inverse analysis. The current approach provides a realistic description of eutectic grain evolution in multicomponent alloys.
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