Fe Based BMG
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Transcript of Fe Based BMG
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Team
Dr. Rajat Kumar Roy (Magnetics Department NML)Rahul Verma
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ObjectiveWe are aiming to make a Iron based Bulk metallic Glass which have a
following properties:-
By having this configuration we can replace traditional metallic Glass with one
which have the higher fracture strength and shows an excellent soft magnetic
property with a higher saturatation magnetization without compromising
with the GFA of the Fe-BMG.
Fracture Strength of 5000Mpa
Large undercoolingtemperatureΔT=40-50°C
Coercivity =3Am-1
Saturation Magnetization= 1.5T
Diameter=2mm
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Argon arc melting
Furnace
➢A BMG can be made by Argon arc melting Furnacein which the material is putted in a vacuum chamberat 10-3Pa and then the melting is done by producingarc thereafter sample is allowed to cool at 10 3K/secwhich result in a rod like material with length of 5cm.
It is noncrystalline in nature
It is soft magnetic material
Low coercivity
High saturation magnetization is desirable
Tremendous hardness
High strength , light weight , high elastic strain
Wear resistance and corrosion resistance is high
More prone catastrophic failure due to formation
of macroscopic shear band
Does not give rise to Braggs Peak
Not contain crystalline defect like point ,line ,stacking fault etc
They are not thermodynamically stable means after
some time it transform back to crystalline groundstate
Degree of undercooling depend on factor likeviscosity interfacial energy, efficiency of nucleatingagent
If in BMG crystalline phase is added it willcalled BMG Composite. In BMG compositeBMG is the matrix and ductile crystalline
phase is the reinforcing medium
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•The glass forming ability of Fe based BMG is increased by Nb , P , C , Cu etc increase the
glass forming ability by increasing the degree of undercooling and prevent crystallization
later
•GFA depend upon the viscosity
•Addition of Nickel and Silicon lead to the improvement of Soft magnetic properties. Large
fraction of metalloid and non metallic element refractory element like Boron , Carbon areresponsible for low saturation magnetization in multicomponent alloy but they increase
the density of glass hence improve the GFA
•Substituting Cu with Ni improve fatigue strength limit and fatigue ratio
ViscosityIncreases
GFA Increases
GFA Increases CP Decreases
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Magnetic screens, magnetic filters, or valves
Magnetic cores for power supplies such as choke coils, common mode and noise filter.
Fe-based bulk glassy alloy will be used as a new engineering and functional material on
parts of micromotors, radio wave clock antennas, watch gears, and other applications
MEMS casings and components
EMP and EMI Shielding
Composite armor
Fuzes and sub-munition components
Used as a core in transformers
In aircraft to collect solar wind
Lighter weight fragmentation devices
In Biomedicine areas
Edged tool applications include knives edges and razor blade
In Tennis Racket
Electro-magnetic device casing
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• In Spaceships
• Power inductor in laptop
•As a magnetoresistance
• Good corrosion resistance property make it ideal for making cutting tools
• Have a brilliant scope in automobile industry because of high strength
• Used as a reinforcing materials.
• Fine jewellery industry is the latest one to brace BMGs due to unique
properties of BMG• In geared motors
• Diaphragm for pressure sensors
• Making uncrushable flash drives
• Optical air drives
BMG is a good
material for
making Cutting
Tools
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Argon Arc Melting
Furnace
Iron based alloy is melted bythis machine in an vacuum
condition . In Argon
atmosphere we melt the alloy
of iron which is allowed to cool
that result in a Fe based Rod
shaped BMG
We will firstly start
our work by Melting
our sample in this
Vibrating Sample
Magnetometry
(VSM)
VSM will measure the magnetic
properties of Iron BMGprepared by us. Here sample is
vibrated sinusoidally through
the help of piezoelectric
material and which will give a
hysteresis curve. Through this
we Get the value of Hc ,Is Tc
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Differential Scanning
Calorimetry
(DSC)
In DSC difference in amount ofheat required to increase
the temperature of a sample
and reference is measured as a
function of temperature .It
measure Tg , Tx , Tl
X-Ray
Diffraction
(XRD)
XRD is an excellent characterizing
tool to determine whether thecrystalline phase is present or
not in materials (sharp Peak).
For Fe based BMG XRD shows a
broad peak because of non
crystalline nature of the
materials.
After VSM we go for
DSC to evaluate
Thermal properties
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• Since we are making a Fe based BMG so our main constituent element
will be Iron and we will use especially these alloying element which are
listed below:-
Silicon Copper Nickel Boron
Aluminium Carbon Chromium Phosphorous
Cobalt Molybednum Niobium Zirconium
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•[(Co0.9Fe0.1)0.75B2Si0.05]96Nb4
Rod
2 570 530 40 3980 0.7 327 0.71
[(Co0.8Fe0.2)0.75B2Si0.05]96Nb4 2.5 580 540 40 4100 1.2 372 0.78
[(Co0.7Fe0.3)0.75B2Si0.05]96Nb4 3.5 587 547 40 4130 1.6 402 0.91
[(Co0.6Fe0.4)0.75B2Si0.05]96Nb4 4 592 550 42 4170 1.8 412 0.97
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Fe72B20Si4Nb4 1.5 611 544 67 294
Fe72B20Si4Nb4 2 612 552 60 297
Fe72B4Si20Nb4 2 603 556 47 4200
Fe63Zr8Co6Al1Mo7B15 1.5 657 581 76
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