The X ray diffractogram for

Powders were characterised by TEM. Fig. 7 shows a representative TEM image from the powders milled for 5 h (N8-5) with its corresponding STEM image. EDX spectrum and compositions ATC 0175 shown for two representative phases: a quasicrystalline particle (1) which compositions related to the one reported in literature [5] and [6] and (2) an area in the matrix showing the presence of Al2O3.
Fig. 8 shows representative TEM images for powders milled for 10 h (N8-10). Fig. 8a shows the presence of an IQC particle as verified by the convergent beam diffraction pattern (CBDP) and Fig. 8b shows a general area of the powder particle showing the Al crystallites. The crystallite sizes were measured by drawing a vertical and a horizontal line on each crystallite. The length of the two perpendicular lines crossings each crystallite size was measured and the average value was taken as the size of the particle. About 50 crystallites of each sample were measured to ensure an accurate value. This process was repeated for powders with different milling times. Thus, sex chromosomes was obtained that the crystallite sizes for N8-10 is 81 ± 18 nm and 53 ± 9 nm for N8-15. Both these values are in agreement with the values obtained by the XRD results (Williamson–Hall method) which gave 89 nm and 51 nm respectively (see Fig. 2a).