Microstructural and Magnetic Behavior of Nanocrystalline Fe-12Ni-16B-2Si Alloy Synthesis and Characterization

Kaouther Zaara,Mahmoud Chemingui,Lluisa Escoda,Joan Saurina,Mohamed Khitouni,Nuria Llorca-Isern,Joan-Josep Suñol

doi:10.3390/met11111679

Kaouther Zaara, Mahmoud Chemingui + Show 5 more

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https://doi.org/10.3390/met11111679

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Abstract

The nanocrystalline Fe70Ni12B16Si2 (at.%) alloy was prepared by mechanical alloying (MA) of elemental powders in a high-energy planetary ball mill. Phase evolution, microstructure, thermal behavior and magnetic properties were investigated. It was found that a body-centered cubic structured solid solution started to form after 25 h milling and a faced-centered cubic structure solid solution started to form after 50 h of milling; its amount increased gradually with increasing milling time. The BCC and the FCC phases coexisted after 150 h of milling, with a refined microstructure of 13 nm and a 10 nm crystallite size. The as-milled powder was annealed at 450 °C and 650 °C and then investigated by vibrating sample magnetometry (VSM). It was shown that the semi-hard magnetic properties are affected by the phase transformation on annealing. The saturation magnetization decreases after annealing at 450 °C, whereas annealing at 650 °C improves the magnetic properties of 150 h milled powders through the reduction of coercivity from 109 Oe to 70 Oe and the increase in saturation magnetization.

Highlights

In recent years, Iron-Nickel alloys have attracted considerable attention in both applied and fundamental science
It has been reported that the addition of other elements to the binary Fe-Ni alloy system is usually followed by significant modifications in terms of microstructural, structural, mechanical, magnetic and other properties
The phase identification and the structural evolution were investigated by X-ray diffraction (XRD) by means of D-500 S equipment (Bruker, Billerica, mechanical alloying (MA), USA) with Cu Kα (λ = 1.5406 Å) radiation

Summary

Introduction

Iron-Nickel alloys have attracted considerable attention in both applied and fundamental science. They are widely used in industrial applications due to their soft magnetic properties, such as narrow hysteresis loops, small magnetic losses and low coercive fields [1,2]. It has been reported that the addition of other elements to the binary Fe-Ni alloy system is usually followed by significant modifications in terms of microstructural, structural, mechanical, magnetic and other properties. We studied the influence of milling time on morphology, phase evolution, and the structure and microstructure of the powders. We investigated the thermal behavior and the influence of heat treatment on structural, microstructural and magnetic properties of the as-milled powders

Materials and Methods

Powder Morphology

Microstructural Analysis