Optimization of microstructure for preparing titanium foam with excellent SEA performance

• This study innovatively integrates the powder metallurgy-space holder method with single-factor design to systematically investigate the effects of porosity (45–65%), compaction pressure (300–600 MPa), and pore-forming agent size (∼23–2000 μm) on titanium foam. It clarifies their impacts on energy absorption and reveals underlying mechanisms, providing a scientific basis for optimization. • An “optimal synergistic range” was identified: 55% porosity balances ligament strength and deformability; 400 MPa compaction ensures stable bonding; 500–580 μm pore agents produce uniform pores. This combination yields an energy absorption density of 74.85 MJ/m 3 and a specific energy absorption of 36.88 J/g, markedly outperforming single-parameter tuning • The work defines quantitative process windows, fills a gap in the “parameter–microstructure–performance” relationship, and offers a practical guide for fabricating high-performance titanium foam. By fine‑tuning standard parameters without equipment upgrades, it enables performance breakthroughs suitable for impact‑protection applications, merging theoretical insight with engineering utility. This study aims to optimize the preparation process of titanium foam with high energy absorption performance. The powder metallurgy-space holder method was adopted to systematically investigate the effects of porosity, compaction pressure, and pore-forming agent particle size on the macro- and microstructure as well as mechanical properties (especially specific energy absorption performance) of titanium foam. The results show that: a porosity of 55% achieves the optimal balance between ligament strength and deformability; a compaction pressure of 400 MPa optimizes powder bonding and avoids residual cracks, thereby obtaining high plateau stress; and a pore-forming agent particle size of 500–580 μm contributes to forming a uniform pore structure and inducing stable plastic collapse. When these three factors act synergistically, the titanium foam achieves an energy absorption density of 74.85 MJ/m 3 and a specific energy absorption of 36.88 J/g. This study clarifies the optimal ranges of various process parameters and provides a theoretical basis for the customized preparation of titanium foam with high energy absorption performance.