Machining mechanism of EEM (Elastic Emission Machining) is investigated in the atomic level by employing first-principles molecular-dynamics simulations. Experimental results have suggested that removal of surface atom occurs through a surface chemical reaction between work and powder surfaces. This reaction is explained that powder particle chemisorbs on work surface capturing a work surface atom, and the powder is succeedingly separated removing the atom from work. In this paper, we analyze this separation process by computer simulation, where the work is taken to be silicon (001) ideal surface and the powder particle is SiO 2 and zRO 2 This analysis shows the following results. Firstly, the machining can occur in the unit of atom without introducing any defect around the machined atom. Secondly, machinability dependency on powder-material consists with experimental results. Finally, weakening of back bonds of machined atom is clarified by the density of state analysis.
