Spherical monosized pure aluminum (Al) particles are successfully fabricated by the pulsated orifice ejection method (POEM). The surface reaction between Al and the graphite crucible is investigated by analysing the microstructure and chemical composition of the materials. No significant chemical reaction occurs between Al and the graphite owing to the crystalline Al oxide (γ-Al2O3) layer generated in the initial state. The γ-Al2O3 layer is clearly observed in all regions between the Al particles and graphite via transmission electron microscopy and confirmed by the selected area diffraction pattern. The morphology of the γ-Al2O3 layer perfectly follows the surface morphology of the graphite crucible, which showed nanoscale roughness. This implies that molten Al could not directly contact graphite even though the surface of the crucible became rough to some extent. However, this passivation phenomenon allowed the successful fabrication of monosized pure Al particles. Therefore, POEM is a useful process at least to manufacture monosized pure Al particles.

Abstract
 1. Introduction
 2. Experimental
 3. Results and Discussion
 4. Conclusions
 References

• Hansang Kwona(Department of materials system engineering, Pukyoung National University, Next Generation Materials Co., Ltd) Corresponding Author