A study on porosity and mechanical properties of the open aluminum metal foam through Spark Plasma Sintering SPD Technique

Abstract Aluminum metal foam, distinguished by its lightweight nature, exceptional strength-to-weight ratio, and distinctive cellular structure, has emerged as a highly promising material with extensive applications across diverse industries. Various fabrication techniques, including the Sintering and Dissolution Process (SDP) and powder metallurgy, have been explored to produce metal foams. However, challenges persist in achieving uniform pore sizes and distributions, especially at temperatures surpassing the base material's melting point. To overcome this hurdle, simultaneous loading and heating during fabrication have been proposed, with Spark Plasma Sintering (SPS) emerging as a viable solution. This study delves into the manufacturing of aluminum metal foam utilizing NaCl space holders via SPS, investigating variations in space holder volume to analyze pore morphology and porosity. Additionally, the mechanical properties of the resulting foams are examined, providing valuable insights into the potential of SPS for crafting aluminum metal open foams with tailored properties. Porosity analysis, conducted through X-ray micro CT, reveals porosity ranging from 55–70% in metal foams with NaCl space holder volume fractions of 60–80%. Notably, a maximum energy absorption capacity of 23 MJ/mm3 is achieved in a metal foam with 57% porosity.