9 / 31
Page 77
April 16-17, 2018 Las Vegas, Nevada, USA
2
nd
Edition of
Graphene & Semiconductors | Diamond Graphite & Carbon Materials Conference
6
th
Edition of
Smart Materials & Structures Conference
&
Journal of Material Sciences and Engineering| ISSN: 2169-0022 | GDCSM-2018 | Volume: 7
About the order-disorder transition in arc melted Fe
3
SiAlx soft alloys
A Boulouma
1,2
, A. Drici
2
and
A. K. Gangopadhahay
3
1
ESTI of Annaba, Algeria
2
University of Annaba, Algeria
3
Washington University in St Louis, USA
T
here is an increasing interest in soft magnetic Fe-Si-Al alloys due to their promising properties for applications in various
fields; however, all these structural and magnetic properties depend on the structure of the composition alloys The Fe-rich
side of the phase diagram of the Fe-Al, Fe-Si and Fe-Al-Si systems presents the same structures; at room temperature, Fe-Al system
is characterized by a wide range of ferromagnetic disordered body centered cubic solid solution (A2) up to 22 at.% Al at room
temperature. On increasing the Al content, the first intermetallic structure is Fe
3
Al with D0
3
cubic structure and it exists over the 18-
32 at.% Al range. The other stable intermetallic structure is FeAl, which is also cubic with B2 structure (CsCl) and it exists over the
range 32-50 at.% Al. The magnetic behavior of ordered Fe-Al alloys is complex in the 27 to 32 at.% Al region where the magnetization
actually decreases with decreasing temperature. It was found that partial substitution of Al by Si leads to significantly improved D0
3
structural stability against ordered B2 structure and disordered A2 structure. Moreover, there have been extensive studies, both
experimentally and theoretically, of order-disorder transitions of Fe-rich ternary alloys. Mutual solid solubility between Fe
3
Al and
Fe3Si is well-established. The solid solubility and the magnetic behavior of Fe
3
(Al,Si) was correlated with the ratio of electron-atom .
Polishchuk and Katsnel´son studied the existence of the ordered phases
α
1 (Fe
3
Al and Fe
3
Si which have D0
3
or BiF
3
type order) and
α
2
(FeAl and FeSi which have B2 or CsCl type order) along the Fe
3
Al-Fe
3
Si section by means of high temperature X-ray diffraction
and recording the disappearance of D0
3
superlattice (111) and (200) reflections as a function of temperature and composition. In this
work, alloys of nominal compositions of sendust Fe
3
SiAlX (X =1, 0.75, 0.5, 0.25). The phase purities of the arc-melted ingots were
studied by x-ray diffraction using a Rigaku D-MaxB X-ray diffractometer with Cu-K
α
radiation. It was found that decreasing Al
leads to more disorder in the alloy by the formation of
α
-Fe solid solution. However, the addition of Al influences both of the lattice
parameter and crystallite size of the Fe
3
Si phase. Results show that the presence of
α
1
-Al
0.3
Fe
3
Si0.7 with a (422) preferred orientation
has been noticed over the 70 at% Fe range.
bouloumaa@gmail.comJ Material Sci Eng 2018, Volume: 7
DOI: 10.4172/2169-0022-C3-098