This study demonstrates the stabilization of Mg-3Ca foams by ex-situ addition of TiB2 particles (D50 = 8.045 μm) as effective agents to enhance foam morphology and stability. TiB2 additions (3 and 5 vol%) delayed cell coarsening and preserved higher circularity by increasing melt viscosity. While Mg-3Ca foams contracted during prolonged foaming (5–15 min), TiB2-containing foams retained and even enhanced their expansion, achieving volumes of 625 % and 652 % compared to 566 % for the base alloy. A single-film stabilization model revealed thicker and smoother films (130 μm to 323 μm) with reduced oxide accumulation in the presence of TiB2 particles, highlighting their role in enhancing foam longevity. Quasi-static compression tests indicated that higher TiB2 content introduced serrated deformation, slightly reducing energy absorption. These findings advance our understanding of particle-stabilized Mg foams, offering new opportunities for lightweight, high-performance materials