Investigation on the effect of strut thickness and heat treatment on the mechanical energetic properties of open cell Ni-foam during a uniaxial compression

This study explores the impact of strut thickness and heat treatment on the microstructure and mechanical properties of open-cell nickel foams (OCNiFs). Key findings include a linear increase in strut thickness with extended electroforming time, resulting in the formation of nickel layers with a cauliflower-like morphology. Heat treatment led to the growth of these structures through recrystallization. Mechanically, heat treatment significantly improved the yield point and energy absorption density of the foams, with the yield point increasing from 1.03 ± 0.05 MPa to 1.76 ± 0.05 MPa, and energy absorption density rising from 0.91 ± 0.05 to 3.45 ± 0.05 mJ/mm 3 . Hardness initially varied with strut thickness, but overall decreased post-heat treatment due to structural homogenization and grain growth. Notably, the sample electroformed for 10 h showed the most substantial hardness change, while the sample electroformed for 4 h exhibited the highest energy absorption after heat treatment.