Study of the Microstructural, Thermal, and Magnetic Properties of High-Energy Ball-Milled Nanocrystalline Fe(Al)

Abstract

In this work, structural, microstructural, thermal, and magnetic properties of a Fe-25at%Al alloy produced by high-energy mechanical milling were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and vibrating sample magnetometry (VSM) techniques. At the early stage of the milling process, three phases, namely, Fe, Al, and Fe(Al), coexist in the milled powder. After 20 h of milling, the results of the refinement of the XRD pattern reveal the formation of the supersaturated bcc-Fe(Al) solid solution with a crystallite size of 10 nm. The DSC curves show several overlapped exothermic peaks associated with the relaxation of the deformed structure and various phase transitions, such as the formation of Al13Fe4 and Fe3Al intermetallic. During milling times, the alloyed samples have a hard-ferromagnetic behavior, where Hc varies from 628 Oe to 746 Oe when the milling time increases from 4 to 40 h. The magnetic properties were related to the microstructural changes.

Aluminium-Silicon Lightweight Thermal Management Alloys with Controlled Thermal Expansion

“…Mechanical alloying was first developed in the 1960s with the aim of fabricating a nickel-based superalloy with homogeneous distribution of oxide reinforcements for gas turbine applications [13]. Since then, many material combinations have been explored [14][15][16][17][18][19][20][21][22][23][24][25][26]. The basic principle is the cyclical welding and fracture of ductile and brittle powders via repetitive impact, resulting in a distribution of reinforcement within the metallic matrix particles [27].…”

“…The basic principle is the cyclical welding and fracture of ductile and brittle powders via repetitive impact, resulting in a distribution of reinforcement within the metallic matrix particles [27]. Optimization of key parameters is however necessary to achieve a homogeneous and stable process [24][25][26]28,29]. This composite powder then acts as an input into downstream consolidation processes such as Hot Isostatic Pressing (HIP) or extrusion.…”

Aluminium-Silicon Lightweight Thermal Management Alloys with Controlled Thermal Expansion

“…Mechanical alloying was first developed in the 1960s with the aim of fabricating a nickel-based superalloy with homogeneous distribution of oxide reinforcements for gas turbine applications [13]. Since then, many material combinations have been explored [14][15][16][17][18][19][20][21][22][23][24][25][26]. The basic principle is the cyclical welding and fracture of ductile and brittle powders via repetitive impact, resulting in a distribution of reinforcement within the metallic matrix particles [27].…”

“…The basic principle is the cyclical welding and fracture of ductile and brittle powders via repetitive impact, resulting in a distribution of reinforcement within the metallic matrix particles [27]. However, the optimization of key parameters is necessary to achieve a homogeneous and stable process [24][25][26]28,29]. This composite powder then acts as an input into downstream consolidation processes, such as hot isostatic pressing (HIP) or extrusion.…”