Achieving Pore Structure Homogenization and Compressive Property Enhancement of AlMn Foams via Controlling Mn Content and Applying Entropy Weight Evaluation

Achieving the stability of pore structure and the enhancement of mechanical properties is the prominent target for aluminum (Al) foam design. In this work, the effects of manganese (Mn) content on the pore structure, mechanical properties, and deformation behavior of AlMn foams are investigated. The results show that the appropriate addition of Mn (1.5 wt%) achieves a remarkable balance between energy absorption capacity (4.37 MJ m −3 ) and pore uniformity (standard deviation of 0.95 mm in average pore size), representing substantial enhancements of 193.28% in yield strength and 385.56% in energy absorption capacity compared to pure Al foams. These enhancements are attributed to a refined pore architecture, finely dispersed Al 6 Mn precipitates, and a sequential collapse mechanism, which collectively enable progressive energy dissipation. The application of the entropy weight method is pioneered in this study to establish a predictive framework for multiobjective design, demonstrating that energy absorption and pore uniformity are crucial factors for the matrix design of Al foams. These findings offer a potential strategy for future engineering applications of metal foam design.