Mechanical alloying of Al70Pd20Mn10 elemental powder mixture

Pure crystalline powders of Al, Pd and Mn were mechanically alloyed using a planetary ball mill (Fritsch P-7) with an intensity setting of 7 in an Ar atmosphere. Formation of an icosahedral phase (i-phase) quasicrystal in mechanically alloyed Al70Pd20Mn10 powder and its structure were examined by X-ray diffraction analysis and transmission electron microscopy. The i-phase quasicrystal with a face-centered 6-dimensional hypercubic lattice was formed in Al70Pd20Mn10 powder milled for 30 h. However, it was found from deconvolution of the X-ray diffraction profile that the i-phase contained other phases, such as Al3Pd2 intermetallic compound and unidentified phases. Electron microscopic observation shows that a number of Al3Pd2 intermetallic compound in the shape of a spot with a diameter of about 10 nm are distributed irregularly throughout the quasicrystalline matrix.