Development of TPMS inspired thin walled structured metal foams from unsorted ferrous scrap through melt route

Abstract

Porous castings are avant-garde materials termed as cellular metals. It showcases attractive characteristics likened to their solid equivalents. Powder metallurgy has been long utilized to manufacture cellular metals using diverse chemicals to attain internal pores, however this method is not viable for hefty components. The proposed methodology in this investigation is capable to produce structured foam using space holders using melt route. Melting and casting of cast iron foam described in this work to develop foam structure inspired by TPMS cellular structure (Schwarz, Modified Schwarz and I-WP). Porosity of 62.4% is achieved through casting route against numerically predicted 65% with a compressive strength of 177.4 MPa. Radiography tests shows that there are no significant defects in the connectivity region and there is full connectivity between pores that is in line with the results attained from pre-cast simulations. Optical projection of the casted sample is done as a confirmatory test for ensuring connectivity. Thickness of as low as 1.5mm is casted with Cast Iron in a structured manner.