## 2 Materials and Methods  
_Processing route._ The stages that were carried out in the processing route developed in this work are described below. First, cast ingots of binary Fe40 Al intermetallic compound were prepared using a high-frequency induction furnace at around 1500 \({}^{\circ}\)C, as shown in Figure 1a. High purity (99.9%) Fe and Al were placed inside a silicon carbide crucible for induction melting. The molten Fe-40 wt.% Al (labeled Fe40 Al hereafter) alloy was poured into a rectangular parallelepiped steel mold and subsequently solidified as it cooled until it reached room temperature; these cooling conditions resulted in a coarse-grained microstructure. Then, in order to pulverize the ingots of the intermetallic compound, small pieces of the ingot with approximate measurements of 1 cm in height \(\times\) 1 cm in length \(\times\) 0.5 cm in width were cut. Then, these small ingot pieces were mechanically struck with a hammer, taking advantage of the fragility of the Fe40 Al intermetallic compound in order to obtain a powder of this material with a particle size of less than 1 mm. Subsequently, the intermetallic composition powders were subjected to mechanical milling, and thus, their final size was obtained at this stage (see a schematic representation in Figure 1b). After, the powder mixture of Al and Fe40 Al was subjected to planetary ball milling for various periods in order to reduce the particle sizes of both phases, obtain a uniform distribution of the Fe40 Al intermetallic compound in Al, and induce the homogenization of the chemical elements in the powder mixture (see the illustrative image in Figure 1c). Then, the powder mixture of the Al and Fe was uniaxially pressed at room temperature in a cylindrical mold, as shown in Figure 1d. Subsequently, the green compacts obtained by uniaxial pressing were subjected to a sintering process in a conventional furnace under an argon atmosphere (see the illustration presented in Figure 1d). The processing parameters of each of the stages involved in the processing route developed in the present work are described as follows. Materials.The elemental powders of metallic Al and intermetallic Fe40 Al (99.9% purity) were blended in a mortar--three-particle volume fractions of 5, 10, and 15% of Fe40 Al intermetallic particles, were added to the aluminum powder. Composite powder.The powder mixture was introduced, under an argon atmosphere, to a hardened steel vial with balls of the same material. Analytical grade methyl alcohol, used as a process control agent, was added at a ratio of 0.003 mL per gram of mixture. Later, the mixture was mechanically milled by utilizing a planetary mill at a speed of 250 RPM during different milling times: 0.5, 1, 2, 4, 6, and 8 h. During the ball milling tests, a balls-to-powder weight ratio of 10:1 was employed. Consolidation of composite powders.The powder mixture that was milled for 8 h was uniaxially pressed by using a pressure of 15 tons with a hydraulic press. The resulting compacts possessed a diameter of 3/8 in and in of height. Then, the green compacts were sintered at 500 \({}^{\circ}\)C for 2 h with subsequent cooling inside the furnace. Characterizations.The evolution of the morphology, the particle size, and the distribution of the chemical elements of the powder mixture were analyzed in a scanning electron microscope (SEM, Stereoscan 440), which was connected to software for energy dispersive spectroscopy (EDS). X-ray diffraction analysis was performed to determine and identify the crystalline structure of the different phases that remained or were formed during milling,  
Figure 1: The processing route developed in the present work, involving melting and casting along with some powder metallurgy techniques of powder. as well as to determine the crystallite size, crystalline state transitions, and the lattice parameters from the X-ray diffraction peaks. To perform this analysis, a Bruker D2 Phaser Diffractometer D500 was utilized, in which a voltage of 30 kV was applied with a current of 20 mA.