Fabrication and compressive properties of K405 alloy hollow sphere foams

K405 alloy hollow sphere foams with average aperture about 3 mm and about 0.1 mm wall thickness are fabricated by hollow sphere method. Firstly the wet spheres which were formed as powder shells from slurries by coating polystyrene cores, were arranged in the body-centered cubic (BCC) way. Subsequently, the spheres stacks were heat-treated in vacuum at 300°C for 40 min to decompose the organic materials, sintered at 1150°C for 150 min. The densities of the finished K405 alloy hollow sphere foams are 0.987, 0.999 and 1.085 g/cm³ respectively. The results of compressive tests show that the deformation behaviors of K405 foam specimens are almost the same. The yield strengths are higher than 25 MPa.