Abstract
Formation mechanism of particle existing density distribution in penetration testing of powder bed is fundamentally discussed. The particle existing density distribution change in penetration testing, of which geometrical the structure is simple and the physical meaning is easier to be understood, is observed by static X-ray radiographs. It is clearly shown that the particle existing density distributions around a plunger exhibit periodicity, reflection at wall, diffraction through a slit and interference between two slits. And the spacial distribution of displacement vector is pointed out to be one of the important factors which determine these phenomenon mentioned above.
