Morphology and Physical Studies of Nanostructured Fe₆₄Cr₃₆ Alloy Elaborated by Ball Milling

Abstract

Nanostructured iron based alloy, elaborated from pure elemental powders by mechanical milling at high energy was studied. The materials obtained were characterized by several techniques, such as X-ray diffraction (XRD), which allowed the dissolution of chromium in the iron phase as a function of milling time. The peaks indicate that the obtained solid solution has the body centred cubic (bcc) structure, for a speed of 250 rpm after 24 hours milling time. The Williamson - Hall analysis method was used to exploit the recorded XRD patterns. The crystallite size of about 14 nm and the microstrain of about 0.90% were obtained for 48 hours of milling. Scanning electron microscopes (SEM) and EDX analysis have confirmed the refining of milled particles as a function of milling time and the homogenization of our powders. The measurement of reflection coefficient has revealed an increase in the microwave absorption versus milling time and has confirmed the formation of our alloy during 24 hours of milling.

Characteristics of Nanostructured Cr₇₅Ni₂₅ Alloy Powders Produced by High-Energy Ball Milling

“…The mechanism of formation of such a lamellar structure (multilayered and elongated) results from the repetitive condensation of powders by cold welding and fracture, as shown in Fig. 4.The mechanism of formation continues until this structure becomes the finest possible [8].…”

“…With an increase in the milling time, it can be clearly seen that the XRD peaks broaden at the diffracting planes (110), ( 200) and (211). As the milling time increases a continuous reduction of grain size is observed [8]. After 12 h of milling, pure Cr and Ni form the Cr 0.8 Ni 0.2 phase.This phenomenon confirmed the dissolution of nickel in chromium solid solution, considered as a disordered Cr-Ni phase with a bcc structure due to the strain accumulated during ball milling process.…”

Structure, Microstructure and Magnetic Properties of Nanostructured Alloys Fe-Nd-B Prepared by Mechanical Alloying

“…The alloy obtained is then milled to obtain a monocrystalline powder; this powder is then oriented in a magnetic field and compacted with different methods [11,12], and then sintered. The purpose of this research is to study the influence of crystallite size reduction on the magnetic properties of the Fe 76 Nd 16 B 8 alloy using high energy mechanical milling [13,14] (mechanical alloying), which is an unconventional production method. Indeed, mechanical alloying [15] is currently considered as a very interesting technique for the development of new materials [16,17].…”