Dynamic Powder Compaction Method by Electromagnetic Force

Hollow cylinder product has been made from aluminum powder by a dynamic compaction method that electromagnetic force shrinks an aluminum tube named as a sheath and utilises deformation of the sheath to compact the aluminum powder. A female screw and a taper can be formed inside of the product by this method. The electromagnetic force appears between the sheath and a solenoid coil according to Flemming's left hand law and can be controlled by discharge energy of a power supply. By using a cylindrical core with high stiffness the sheath shrinks uniformly without wrinkles and the aluminum powder can be compacted uniformly. The compacted powder compact, which was sintered at 893 K for 1 hour in a vacuum furnace, has shown about 2.0g/cm3 of density and 50MPa of compression failure strength. The density and strength increase with an increase in the discharge energy. However, the strength has decreased due to applying the same electromagnetic force on the sheath repeatedly.