SolidificationSolidification microstructuresMicrostructure can be manipulated under certain conditions, particularly during directional solidificationDirectional solidification (DS), which allows for a controlled transition from liquid to solid by managing the thermal gradient and interfacial velocity. In this study, an aluminumAluminum-rich hypo-monotectic system, Al–8wt%In, was directionally solidified and was characterized using micro-computed tomography, revealing a banded microstructureBanded microstructures along the entire length of the sample. We observed a periodic transition among three different morphologies: a pure primary aluminumAluminum phase, a string of droplets sometimes referred to as ‘pearls’, and a random distributionDistribution of indium-rich particles within the primary aluminumAluminum phase. Understanding the interactions between particles and the solid–liquid (SL) interface is crucial for controlling particle distributionDistribution, which offers potential for future industrial applications in particle-based castingsCasting. However, challenges remain in understanding the mechanism for controlling these banded structures due to the non-periodic spacing of the bands observed in our results, as well as the possibility of the presence of external factors such as natural andAl-In Marangoni convection.