Fabrication and filtration efficiency of porous sintered bodies using shape-controlled 316L stainless steel powders by high-energy ball milling

This study investigates the effects of powder size and shape on the properties of metallic porous bodies fabricated by powder metallurgy, with a particular focus on filtration efficiency. High-energy ball milling was performed on spherical stainless steel powder using a planetary ball mill, with process variables including ball size and rotational speed. The milled powders were then fabricated into metallic porous bodies through compaction and sintering, followed by filtration tests. The analysis indicated that larger ball sizes led to coarser powder particles, and higher rotational speeds transformed the powder shape from plate-like to needle-like. Filters produced with needle-like powders exhibited more complex pore structures, resulting in higher filtration efficiency despite similar porosity. These findings demonstrate that powder shape significantly influences the filtration properties of metallic filters manufactured via powder metallurgy.