This study focused on developing microstructural, thermal, and radiation shielding changes in Al50Si25B25 powders using mechanical alloying techniques. Based on the x‐ray powder diffraction data, the crystallite size and microstrain of the 100‐hours milled powder were calculated as 0.25 nm and 50.33 %, respectively. The solubility of silicon in the α‐aluminium matrix increased with longer mechanical alloying duration. Transmission electron microscope analyses further showed that the alloy particulates had an average size of 3 μm and an average grain size of 0.226 nm. The radiation shielding properties of the Al50Si25B25 powders indicated that the Linear Attenuation Coefficient value increased from 0.0554±0.1689 cm−1 to 1.0632±0.2425 cm−1 with an increase in the thickness of the Al50Si25B25 alloy. This work successfully demonstrated the potential of mechanical alloying techniques to enhance the microstructural and thermal properties of Al50Si25B25 powders. It highlighted their effectiveness in providing radiation shielding capabilities when varying the thickness of the alloy.