Composite metal foams processed through powder metallurgy

A new closed cell composite metal foam has been produced using a powder metallurgy technique. The composite foams are processed by filling the vacancies between densely packed steel hollow spheres with steel powder and sintering them into a solid cellular structure. Three sets of samples have been processed, two of carbon steel and one of stainless steel. The relative densities of the products were in the range of 32.4–38.9%. Although denser than other foams, the materials developed in this study display superior compressive strengths and energy absorption capabilities, which caused superior strength to density ratios in our samples compared to other foams made from similar materials. The plateau strength to density ratio for the carbon steel samples were in the range of 12–31.9 MPa/(g/cm3) and for stainless steel samples 43.7 MPa/(g/cm3). The energy absorption at densification for carbon steel samples ranged from 18.9 to 41.7 MJ/m3 and for the stainless steel sample 67.8 MJ/m3.