Process and properties of porous metal aluminum fabricated by material extrusion forming

Porous metal aluminum， a low-density metallic foam with a porous structure， exhibits good energy absorption and sound absorption properties， leading to its wide application in fields such as machinery manufacturing and aerospace. Currently， the fabrication of porous aluminum primarily relies on physical or electrochemical methods， which often involve complex processes and high costs. This study employs a low-cost material extrusion forming technique to prepare porous metal aluminum， investigates its forming characteristics， and systematically examines the effects of aluminum-based slurry solid content， forming parameters， and sintering processes on the properties of the extruded porous metal aluminum， and the pore structure is optimized to prepare porous metal aluminum. The results show that when the solid content of the aluminum-based slurry is 80%（mass fraction）， the desired billet can be extruded completely without collapse or depression. Using process parameters of a needle diameter of 0.34 mm， a layer height of 0.22 mm， and a filling rate of 50% to prepare the billet. The porous metal aluminum obtained by sintering at 650 ℃ and holding for 150 min has good properties， with a flexural strength of 12.57 MPa， a porosity of 53.96%， and a shrinkage rate of 3.19%， meeting the performance requirements for porous metal aluminum.