fe based bmg

8/16/2019 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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fe based bmg

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