# Al-Fe-Ni Metallic Glasses via Mechanical Alloying and Its Consolidation
## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Milling Time (h)**} & \multicolumn{4}{c}{**The Portion of Particles with Diameters Smaller than Cumulative 10, 50 and 90\%**} \\ \cline{2-6}  & \multicolumn{3}{c}{**MA at Speed of 250 rpm**} & \multicolumn{3}{c}{**MA at Speed of 350 rpm**} \\ \cline{2-6}  & **D\({}_{\text{10}}\) (\(\upmu\)m)** & **D\({}_{\text{50}}\) (\(\upmu\)m)** & **D\({}_{\text{90}}\) (\(\upmu\)m)** & **D\({}_{\text{10}}\) (\(\upmu\)m)** & **D\({}_{\text{50}}\) (\(\upmu\)m)** & **D\({}_{\text{90}}\) (\(\upmu\)m)** \\ \hline
5 & 15.4 & 26.6 & 37.8 & 11.4 & 23.3 & 47.8 \\
10 & 11.1 & 21.8 & 37.0 & 11.0 & 21.2 & 39.3 \\
20 & 6.4 & 11.8 & 21.4 & 11.4 & 22.8 & 37.0 \\
40 & 8.7 & 18.0 & 41.8 & 7.9 & 13.6 & 22.2 \\
60 & 6.2 & 11.1 & 19.4 & 5.8 & 9.5 & 14.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Characteristics of particle size distributions for powders after MA,. Figure 3: The typical particles size distribution of Al\({}_{\text{82}}\)Fe\({}_{\text{14}}\)Ni\({}_{\text{4}}\) alloy powders milled at (a) 250 rpm for 60 h and (b) 350 rpm for 60 h; cumulative distribution of the alloy powders milled at (c) 250 rpm and (d) 350 rpm. welding that was taking place. Figure 3a,b compares the cumulative size distribution curve of powders milled for different times and speeds. The cumulative size distribution curve shifted leftwards, indicating that particle size shifted to a smaller micron range (<19.4 \(\upmu\)m and 14.6 at 90% volume fraction for powders milled at 250 and 350 rpm, respectively). The XRD profiles of the as-milled Al\({}_{82}\)Fe\({}_{14}\)Ni\({}_{4}\) powders after different milling times are given in Figure 4. The XRD patterns obtained for both powders milled after 5 h show all of the characteristic peaks corresponding to the constituent elements of Al (PDF#04-0787), Fe (PDF#06-0696) and Ni (PDF#04-0850). For the powders milled at 350 rpm, the diffraction peaks were broadened compared with those of powders milled at 250 rpm. Moreover, a broad halo peak corresponding to an amorphous phase could be detected in the 20 range of 40-50\({}^{\circ}\) for powders milled at 350 and 250 rpm after 10 and 20 h milling, respectively. The amorphization started seeming to be earlier in powders milled at 350 rpm. Powders milled at 250 rpm have lower impact energy than those of 350 rpm, leading to slower amorphization in the earlier milling state (up to 20 h). After a milling time of 60 h, the width of the diffraction pattern was further increased, and all crystals disappeared for both alloy powders. Only a broad diffuse halo remained to indicate the XRD amorphous phase in both cases, the same as in [PERSON]'s observation of a hollow peak found for full amorphous Al\({}_{82}\)La\({}_{10}\)Fe\({}_{4}\)Ni\({}_{4}\) alloy after 350 h of milling [29]. The alloying process in this system was due to the relatively high negative heats of the mixing of the Al-Fe, Al-Ni and Fe-Ni pairs being \(-\)11, \(-\)22 and \(-\)2 kJ/mol, respectively [28]. The hysteresis loops of Al\({}_{82}\)Fe\({}_{14}\)Ni\({}_{4}\) alloys milled at 250 and 350 rpm after different milling times are presented in Figure 5a,b. All curves present the sigmoidal shape and do not reach the completely saturated state at applied fields as high as 15,000 Oe. The small hysteresis losses are the properties generally desired in soft magnetic materials [39]. The values of the saturation magnetization (M\({}_{8}\)) and coercivity (H\({}_{\rm c}\)) of Al\({}_{82}\)Fe\({}_{14}\)Ni\({}_{4}\) alloys with the increase of milling time are given in Table 3. For Al\({}_{82}\)Fe\({}_{14}\)Ni\({}_{4}\) alloys, the M\({}_{8}\) values of powders milled at 250 rpm and 350 rpm are decreased from the maximum 35.27 emu/g and 20.76 emu/g (5 h of milling) to the minimum 4.75 emu/g and 0.37 emu/g (60 h of milling), respectively. It is reported that the saturation magnetization of Al\({}_{82}\)Fe\({}_{14}\)Ni\({}_{2}\)Y\({}_{2}\) amorphous alloys prepared by MA [40] were about 0.8 emu/g. [PERSON] et al.