# Al-Fe-Ni Metallic Glasses via Mechanical Alloying and Its Consolidation
## 1 Introduction  
Al-based metallic glasses have great potential in applications requiring high corrosion resistance, high wear resistance, high strength and relatively low density [1; 2; 3; 4; 5]. Al-based metallic glasses contain Al contents of higher than 80 at.% of the base component with a deep eutectic, which is a common factor for easy glass formation [4; 5; 6; 7; 8; 9]. Due to a lack of regular long-range order within their atomic structures, amorphous materials have no detectable crystal structure [2]. Therefore, amorphous alloys possess superior properties than those of crystalline alloys [2; 7]. It was reported that most Al-based amorphous alloys have a high tensile strength, as much as 1000 MPa, which is about twice as high as that of conventional high-strength aluminum alloys [1; 10; 11]. Among the Al-based amorphous alloys, Al-Fe alloys have attracted technological interest because they possess high specific strength and excellent corrosion resistance at elevated temperatures under sulfidizing, oxidizing and carburizing environments [12; 13]. Generally, there are several preparation methods for Al-based amorphous alloys, such as melt-spinning [1; 14; 15; 16], powder metallurgy [17] and casting [1; 18] and mechanical alloying (MA) [19; 20]. Among these methods, MA provides some advantages for producing amorphous alloys, such as a wide selection of suitable compositions of materials, lower preparation cost, easier process control, material savings and mass production [21]. Accordingly, mechanical alloying allows for the alloying of powder in the solid state, avoiding melting and solidification. MA is a ball-milling process where a powder mixture placed in the ball mill is subjected to a high-energy collision from the balls. The most important events involved in mechanical alloying are the repeated cold welding, fracturing and rewelding of the powder mixture; it is critical to establish a balance between the processesin order to alloy successfully. MA is now recognized as a unique method for synthesizing a range of equilibrium and non-equilibrium alloy phases beginning with a mixture of elemental or pre-alloyed powders. Supersaturated solid solutions, metastable crystalline and quasi-crystalline phases, nanostructures and amorphous alloys are among the non-equilibrium phases prepared [22; 23; 24; 25; 26]. As intermediate phases generated in mechanically alloyed powders can be magnetic or nonmagnetic, their total magnetic characteristics rely on their phase compositions and microstructures. Nanocrystalline soft magnetic materials' coercive forces rely on their crystallite sizes. Various milling intensities and times yield alloy powders with different coercive forces. Studying the saturation magnetization of alloys is also important, as reducing the grain size to the single magnetic domain size eliminates magnetic barriers [27]. Al-based metallic glasses, such as Al-Fe-La, Al-Fe-Ni-La and Al-V-Fe-Cu, typically have a minor positive heat of mixing. For those alloys, this leads to a long milling time to reach a fully or partially amorphous structure by mechanical alloying. Meanwhile, the enthalpy of mixing values of binary pairs Fe-La and Fe-Cu are 5 and 13 kJ/mole, respectively [28]. [PERSON] et al. took 350 h to obtain a fully amorphous Al\({}_{82}\)Fe\({}_{14}\)Ni\({}_{4}\)La\({}_{10}\) structure by mechanical alloying using a planetary ball mill [29]. [PERSON] et al. observed that the glass-forming ability (GFA) of Al\({}_{75}\)V\({}_{12.5}\)Fe\({}_{12.5-x}\)Cu\({}_{x}\) alloys, prepared by mechanical alloying, decreased with an increase of copper content [30]. In order to improve the GFA of Al-Fe based systems, it is necessary to select the elemental metals with negative mixing enthalpy among atomic pairs of elements, such as Al-Fe-Y, Al-Fe-Ti and Al-Fe-Ni [28; 31; 32]. In Al-Fe-Ni systems, enthalpies of mixing between binary elements Al-Fe, Al-Ni and Fe-Ni are \(-11\), \(-22\) and \(-2\) kJ/mole [28], respectively, which are favorable for GFA.