Ionel Chicina Department of Materials Science and Technology, - - PowerPoint PPT Presentation

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Ionel Chicina Department of Materials Science and Technology, - - PowerPoint PPT Presentation

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SOFT MAGNETIC NANOCRYSTALLINE/NANOSTRUCTURED SOFT MAGNETIC NANOCRYSTALLINE/NANOSTRUCTURED MATERIALS PRODUCED BY MATERIALS PRODUCED BY MECHANICAL ALLOYING ROUTES MECHANICAL ALLOYING ROUTES Ionel Chicina Department of Materials Science and

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SLIDE 1

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 1

SOFT MAGNETIC NANOCRYSTALLINE/NANOSTRUCTURED SOFT MAGNETIC NANOCRYSTALLINE/NANOSTRUCTURED MATERIALS PRODUCED BY MATERIALS PRODUCED BY MECHANICAL ALLOYING ROUTES MECHANICAL ALLOYING ROUTES

Ionel Chicinaş

Department of Materials Science and Technology, Technical University of Cluj-Napoca, Romania

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SLIDE 2

What are Nanocrystalline Materials ? Polycrystalline materials

Crystallite (grain) D = 0.1-102 µm Grain limits

schematic

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 2

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SLIDE 3

What are Nanocrystalline Materials ? Polycrystalline materials

Crystallite (grain) D = 0.1-102 µm Grain limits

schematic

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 2

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SLIDE 4

What are Nanocrystalline Materials ? Polycrystalline materials

Crystallite (grain) D = 0.1-102 µm Grain limits

schematic

Real images European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 2

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SLIDE 5

What are Nanocrystalline Materials ? Polycrystalline materials

Crystallite (grain) D = 0.1-102 µm Grain limits

schematic

Real images

Nanocrystalline materials

Crystallite (grain) D = 1-100 nm Grain limits Atoms in grains Atoms in limits European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 2

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SLIDE 6

What are Nanocrystalline Materials ? Polycrystalline materials

Crystallite (grain) D = 0.1-102 µm Grain limits

schematic

Real images

Nanocrystalline materials

Crystallite (grain) D = 1-100 nm Grain limits Atoms in grains Atoms in limits

D ∆ F 3 =

Fraction of atoms in limits

Crystallite size Grain limit thickness

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 2

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SLIDE 7

What are Nanocrystalline Materials ? Polycrystalline materials

Crystallite (grain) D = 0.1-102 µm Grain limits

schematic

Real images

Nanocrystalline materials

Crystallite (grain) D = 1-100 nm Grain limits Atoms in grains Atoms in limits

D ∆ F 3 =

Fraction of atoms in limits

Crystallite size Grain limit thickness

Examples:

D = 5 nm F = 50% D = 10 nm F = 30% D = 100 nm F = 3%

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 2

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SLIDE 8

Why are important Nanocrystalline Materials ? What really means the Nanocrystalline Materials ? When a Material is really Nano?

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 3

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SLIDE 9

What are important Nanocrystalline Materials ? What really means the Nanocrystalline Materials ? When a Material is Nano? For example: Coercive field HC

depend on intrinsic properties (anisotropy) structure (grain size, stresses, inclusions,etc. European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 3

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SLIDE 10

What are important Nanocrystalline Materials ? What really means the Nanocrystalline Materials ? When a Material is Nano? For example: Coercive field HC

depend on intrinsic properties (anisotropy) structure (grain size, stresses, inclusions,etc.

Polycrystalline materials

HC when D and

HC ~ 1/D

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 3

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SLIDE 11

What are important Nanocrystalline Materials ? What really means the Nanocrystalline Materials ? When a Material is Nano? For example: Coercive field HC

depend on intrinsic properties (anisotropy) structure (grain size, stresses, inclusions,etc.

Polycrystalline materials

HC when D and

HC ~ 1/D Nanocrystalline materials

HC when D and

HC ~ D6

  • G. Herzer, Scripta Metall et Mater., 33 (1995) 1741-1756.

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 3

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SLIDE 12

What are important Nanocrystalline Materials ? What really means the Nanocrystalline Materials ? When a Material is Nano? For example: Coercive field HC

depend on intrinsic properties (anisotropy) structure (grain size, stresses, inclusions,etc.

Polycrystalline materials

HC when D and

HC ~ 1/D Nanocrystalline materials

HC when D and

HC ~ D6

  • G. Herzer, Scripta Metall et Mater., 33 (1995) 1741-1756.

A Material is Nanocrystalline when its Crystallite Size is lower then the Interaction Length of the considered Property!

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 3

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SLIDE 13

Nanocristalline/nanostructured (d < 100 nm) materials can be produced starting from:

  • vapours - inert gas condensation, sputtering, plasma processing,

CVD

  • liquid -

electrodeposition, rapid solidification

  • solid -

mechanical alloying, mecanosynthese, severe plastic deformation, spark erosion

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 4

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SLIDE 14

Mechanical alloying

Nanocristallins/nanostructured magnetic materials

annealing modifies

the structure and the microstructure Nanocristallin/nanostructured (d < 100 nm) materials can be produced starting from:

  • vapours - inert gas condensation, sputtering, plasma processing,

CVD

  • liquid -

electrodeposition, rapid solidification

  • solid -

mechanical alloying, mecanosynthese, severe plastic deformation, spark erosion

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 4

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SLIDE 15

Mechanical routes for producing nanocrystalline powders

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 5

What is mechanical alloying?

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SLIDE 16

Mechanical alloying (MA) involves the synthesis

  • f

materials in solid state by high-energy ball milling

Mechanical routes for producing nanocrystalline powders

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 5

Usually, we make alloys by melting together the components What is mechanical alloying?

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SLIDE 17

Mechanical alloying (MA) involves the synthesis

  • f

materials in solid state by high-energy ball milling

Mechanical routes for producing nanocrystalline powders

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 5

Usually, we make alloys by melting together the components What is mechanical alloying? Elemental Powders Mixture Milling in high energy ball mill

  • Particles and grains are fractured
  • Defects introduced in particles
  • Temperature rise - diffusion

New phase

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SLIDE 18

Mechanical alloying (MA) involves the synthesis

  • f

materials in solid state by high-energy ball milling

Mechanical routes for producing nanocrystalline powders

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 5

Usually, we make alloys by melting together the components What is mechanical alloying? Elemental Powders Mixture Milling in high energy ball mill

  • Particles and grains are fractured
  • Defects introduced in particles
  • Temperature rise - diffusion

New phase

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SLIDE 19

Mechanical alloying (MA) involves the synthesis

  • f

materials in solid state by high-energy ball milling

Mechanical routes for producing nanocrystalline powders

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 5

Usually, we make alloys by melting together the components What is mechanical alloying? Elemental Powders Mixture Milling in high energy ball mill

  • Particles and grains are fractured
  • Defects introduced in particles
  • Temperature rise - diffusion

New phase C1 C2 C3

D1 D2 D1 B1 B1 B2

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SLIDE 20

European School on Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 6

Mechanical alloying (MA) involves the synthesis

  • f

materials by high-energy ball milling - PROCESS Ω

Disc Vial

ω Mechanical milling (MM) refers to the process

  • f

milling pure metals

  • r

compounds without solid state reaction Ω » ω → shock mode process (SMP) Ω « ω → friction mode process (FMP)

Mechanical routes for producing nanocristalline powders

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SLIDE 21

European School on Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 6

Mechanical alloying (MA) involves the synthesis

  • f

materials by high-energy ball milling - PROCESS Ω

Disc Vial

ω Mechanical milling (MM) refers to the process

  • f

milling pure metals

  • r

compounds without solid state reaction Ω » ω → shock mode process (SMP) Ω « ω → friction mode process (FMP)

Mechanical routes for producing nanocristalline powders

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SLIDE 22

European School on Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 6

Mechanical alloying (MA) involves the synthesis

  • f

materials by high-energy ball milling - PROCESS Ω

Disc Vial

ω Mechanical milling (MM) refers to the process

  • f

milling pure metals

  • r

compounds without solid state reaction Ω » ω → shock mode process (SMP) Ω « ω → friction mode process (FMP)

Mechanical routes for producing nanocristalline powders

factors related to material or materials mixture subjected to milling. Factors depending upon the milling equipment, including the milling bodies Factors depending upon processing

Milling:

Dry milling Wet milling Cryomilling

Three groups of parameters were identified, depending on:

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SLIDE 23

European School on Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 6

Mechanical alloying (MA) involves the synthesis

  • f

materials by high-energy ball milling - Equipments Ω

Disc Vial

ω Mechanical milling (MM) refers to the process

  • f

milling pure metals

  • r

compounds without solid state reaction Ω » ω → shock mode process (SMP) Ω « ω → friction mode process (FMP)

Mechanical routes for producing nanocristalline powders

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SLIDE 24

Mechanical Alloying and Annealing Combining (MAAC) - What is this technique?

MA

Generally, synthesis of new material by MA needs a long time What's happening if we STOP the milling process before the mechanical alloying finishing and then we make an annealing?

Annealing the mixture milled

  • V. Pop, O. Isnard and I. Chicinas, J. Alloys and Comp., 361 (2003), p.144-152.

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 7

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SLIDE 25

MAAC MAAC – can reduce the synthesis time!

Mechanical Alloying and Annealing Combining (MAAC) - What is this technique?

MA

Generally, synthesis of new material by MA needs a long time What's happening if we STOP the milling process before the mechanical alloying finishing and then we make an annealing?

It is `possible to improve (finishing) the solid state reaction of compound/alloy forming!

Annealing the mixture milled

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 7

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SLIDE 26

Reactive milling (RM) Mechanochemistry (MC)

(dry or wet MM)

The MC consists of: a. reduction of the grain size below a certain value b. the subsequent chemical reaction towards the equilibrium phase composition under the milling conditions.

MO + R → M + RO (it is applied for oxides, chlorides, sulphurs, etc.)

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 8

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SLIDE 27

80 20 40 60 100 τ0 τ1 τ3 τ2 τ4 time

germi- nation development Saturation/ finishing

initiation

20%Ni

3Fe+

80%(3Ni+Fe) 80 20 40 60 100 Ni3Fe percentage τ0 τ1 τ3 τ2 τ4 time

development Saturation/ finishing

initiation

3Ni+Fe 20%Ni

3Fe+

Mechanical Alloying in the Presence of Nanocrystalline Germs

  • f the same Product

n mB

A nB mA = +

n m n m

B A B A x nB mA x = ⋅ + + ⋅ − ) ( ) 1 (

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 9

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SLIDE 28

80 20 40 60 100 τ0 τ1 τ3 τ2 τ4 time

germi- nation development Saturation/ finishing

initiation

20%Ni

3Fe+

80%(3Ni+Fe) 80 20 40 60 100 Ni3Fe percentage τ0 τ1 τ3 τ2 τ4 time

development Saturation/ finishing

initiation

3Ni+Fe 20%Ni

3Fe+

Mechanical Alloying in the Presence of Nanocrystalline Germs

  • f the same Product

n mB

A nB mA = +

n m n m

B A B A x nB mA x = ⋅ + + ⋅ − ) ( ) 1 (

  • Z. Sparchez, I. Chicinas, O. Isnard, V. Pop, F. Popa, J. Alloys and Compounds, 434–435 (2007) 485–488

Ni3Fe

Ni3Fe Ni

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 9

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SLIDE 29

Z n F e2 O4 , C u F e2 O4, MeFe2O4 Me = Mg, Cu, Ni,

Mechanical routes for producing of ferrites

Annealing produces

  • nly spinel phase

Polycrystalline ferrite produced by solid state reaction (ceramic method) Stoichiometric mixture

  • f oxides or of oxides

and hidroxicarbonate Low temperature chemical co-precipitation (nanosized ferrite) Mechanical milling

(dry or wet milling)

Mechanical milling

(dry or wet milling)

Mechanochemistry

(dry or wet milling)

Soft magnetic nanocrystalline (nanosized) ferrites ≈80-95 %

spinel phase MeFe2O4, Me = Mn, Cu, Zn, Ni ZnFe2O4 European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 10

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SLIDE 30

Partial reversibility during milling of the reaction:

G.F. Goya, H.R. Rechenberg, J. Phys: Condens. Mater., 10 (1998) 11829-11840 G.F. Goya, H.R. Rechenberg, J.Z. Jiang, J. Appl. Phys. 84 (1998) 1101-1108 F .Padella et al. Mater. Chem. Phys. 90 (2005) 172-177

α-Fe2O3 + MeO ↔ MeFe2O4

Structural properties, phase composition

The particles contain several related Fe–Me–O phases

Milling in closed vial: α-Fe2O3 is reduced at Fe3O4 Milling in open vial: neither reduction of Fe3+ were detected Particle size is generally reduced under 10 nm

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 11

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SLIDE 31

Magnetic behaviour of mechanosyntesized ferrites

The magnetic properties are associated with the canted spin configuration in small particles the non-equilibrium cation redistribution resulting in a decrease of the number of magnetic Fe3+(A)-O2--Fe3+(B) linkages Coexistence of both ferrimagnetic and superparamagnetic phase Magnetisation does not saturated even in an applied field of 9 T Ms decrease with milling time as a result of spin canting effect The hysteresis loop is not symmetrical about the origin and is shifted to the left

∆HC which increases with increasing the milling time European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 12

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SLIDE 32

Mechanical routes used for producing SMA MA MAAC

Two-step MA

MAAC

with inoculated germs

MC*

MM of oxides blend reduction of oxides alloying by heat treatment

  • btaining nanocrystalline

alloy by MA

  • btaining nanocrystalline alloy by MM

*X.Y. Qin, S.H. Cheong, J.S. Lee, Mater. Sci. Eng., A 363 (2003) 62

Soft Magnetic Nanocrystalline Powders

Raw materials used – generally elemental powders Milling equipment used - generally planetary ball mill Ball/powder mass ratio : very different (from 5:1 to 30:1) European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 15

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SLIDE 33

Fe-Cu powders obtained by MA

fcc bcc bcc + fcc 4 8 12 16 20 24 28 80 90 100 0 10 20 30 40 60 70 50

%Cu Milling time (h)

fcc bcc bcc + fcc 4 8 12 16 20 24 28 4 8 12 16 20 24 28 80 90 100 0 10 20 30 40 60 70 50 80 90 100 0 10 20 30 40 60 70 50

%Cu Milling time (h)

Milling map of mechanically alloyed Fe-Cu system

  • B. Majumdar et al., J. Alloys Comp. 248, 192 (1997)

Extended solid solution!!! European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 13

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SLIDE 34

Fe-Cu powders obtained by MA

fcc bcc bcc + fcc 4 8 12 16 20 24 28 80 90 100 0 10 20 30 40 60 70 50

%Cu Milling time (h)

fcc bcc bcc + fcc 4 8 12 16 20 24 28 4 8 12 16 20 24 28 80 90 100 0 10 20 30 40 60 70 50 80 90 100 0 10 20 30 40 60 70 50

%Cu Milling time (h)

Fe80Cu20

R.B. Schwarz, T.D. Shen, U. Harms, T. Lollo, J. Magn. Magn.

  • Mater. 283, 223 (2004).

Milling map of mechanically alloyed Fe-Cu system

  • B. Majumdar et al., J. Alloys Comp. 248, 192 (1997)

Extended solid solution!!! Interesting magnetic properties European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 13

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SLIDE 35

Why Ni-Fe and Ni-Fe-X-(Y) systems?

Polycrystalline Ni-Fe and Ni-Fe-X alloys have very good SMP

Why mechanical alloying techniques?

Nanocrystalline materials have very good SMP

It is possible to combine the properties of Ni-Fe and Ni-Fe-X-(Y) systems with the properties of nanocrystalline state Ni-Fe and Ni-Fe-X-(Y) systems

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 14

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SLIDE 36

Why Ni-Fe and Ni-Fe-X-(Y) systems?

Polycrystalline Ni-Fe and Ni-Fe-X alloys have very good SMP

Why mechanical alloying techniques?

Nanocrystalline materials have very good SMP

It is possible to combine the properties of Ni-Fe and Ni-Fe-X-(Y) systems with the properties of nanocrystalline state Ni-Fe and Ni-Fe-X-(Y) systems

10 20 30 40 50 60 70 80 90 100 200 800 600 400

γ-fcc

α-bcc

Ni3Fe

Fe Ni

Atomic percent Nickel Temperature (°C)

bcc+fcc bcc bcc+fcc bct fcc

40% [86,99] 50% [86, 96, 100] 60% [86] 70% [86] 80% [86, 115] 90% [86] [ 1 6 , 1 7 , 9 6 , 1 4 , 1 1 2 , 1 1 , 1 3 , 1 1 4 ] 38% [86] 36% [86] 34% [86] 32% [86] 30% [86,100] 28% [86] 26% [86] 22% [86] 11.11% [84] 20% [96,86] 14.4% [94] 9.09% [84] 7.69% [84] 1 % [ 8 6 ] 2 4 . 1 % [ 9 7 ] 75%

bcc+fcc bct [97] bct bct+fcc [98]

19.2% [93, 97] 9 . 6 % [ 9 3 ] 24% [86] 2 9 % [ 9 7 , 9 8 ] 3 3 . 9 % [ 9 7 , 9 8 ] 3 5 % [ 9 6 , 9 9 ]

bcc+fcc [99, 100] bcc+fcc [99]

2 7 , 5 % [ 9 9 ] 2 5 % [ 9 9 ] 2 2 . 5 % [ 9 9 ] 85% [93]

10 20 30 40 50 60 70 80 90 100 10 20 30 40 50 60 70 80 90 100 200 800 600 400

γ-fcc

α-bcc

Ni3Fe

Fe Ni

Atomic percent Nickel Temperature (°C)

bcc+fcc bcc bcc+fcc bct fcc

40% [86,99] 50% [86, 96, 100] 60% [86] 70% [86] 80% [86, 115] 90% [86] [ 1 6 , 1 7 , 9 6 , 1 4 , 1 1 2 , 1 1 , 1 3 , 1 1 4 ] 38% [86] 36% [86] 34% [86] 32% [86] 30% [86,100] 28% [86] 26% [86] 22% [86] 11.11% [84] 20% [96,86] 14.4% [94] 9.09% [84] 7.69% [84] 1 % [ 8 6 ] 2 4 . 1 % [ 9 7 ] 75%

bcc+fcc bct [97] bct bct+fcc [98]

19.2% [93, 97] 9 . 6 % [ 9 3 ] 24% [86] 2 9 % [ 9 7 , 9 8 ] 3 3 . 9 % [ 9 7 , 9 8 ] 3 5 % [ 9 6 , 9 9 ]

bcc+fcc [99, 100] bcc+fcc [99]

2 7 , 5 % [ 9 9 ] 2 5 % [ 9 9 ] 2 2 . 5 % [ 9 9 ] 85% [93]

SMC powders produced by MA

  • V. Pop, I. Chicinaş, J. Optoelectron. Adv. Mater. 9 (2007), 1478-1491

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 14

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SLIDE 37

It has been proved that the milling performed in the friction mode (FMP) leads to the formation of alloys exhibiting a soft magnetic behaviour. However, magnetisation is not affected by the mode used In high-energy ball milling process the fcc solid solution γ(Fe,Ni) in alloys Fe65Ni35 was formed after 36 hours, while in the low-energy milling process the Fe lines disappeared after 400 hours of milling.

  • R. Hamzaoui, O. Elkedim, E. Gaffet, J. Mater. Sci., 39 (2004) 5139

Properties depending of milling conditions

  • E. Jartych, J.K. Żurawicz, D. Oleszak, M. Pękała, J. Magn. Magn. Mater. 208 (2000) 221

A strong decrease of the coercive field versus crystallite size appears especially for crystallite size smaller than 20 nm

  • R. Hamzaoui, O. Elkedim, N. Fenineche, E. Gaffet, J. Craven,
  • Mater. Sci. Eng. A 360 (2003) 299-305

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 15

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SLIDE 38

ss 1h 1h+330°C/1h 2h 2h+ 330°C/1h 3h 3h+330°C/1h 4h 4h+330°C/1h 6h 6h+330°C/1h 8h 8h+330°C/1h 10h 10h+330°C/1h 12h 12h+330°C/1h

Intensité (unit. arb.) 2 theta (degrés)

3 6 40 50 60 70 8 9

40 50 60 70 80 90

2 θ (°)

Intensity (a.u.)

Fe Fe Ni3Fe Ni

peaks shift to LOWER 2θ angles peaks shift to HIGHER 2θ angles broadening of the diffraction peaks

  • Ni3Fe phase formation
  • the first order internal stresses

relaxion of the first order internal stresses the second order internal stresses Crystallite size reduction

  • I. Chicinas et al. J. Alloys and Compounds 352 (2003), p. 34-40.

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 16

slide-39
SLIDE 39

Ni3Fe Ni

Intensité (u.a.) 2 th e ta

8 9 .2 9 0 9 1 9 2 9 3 9 4 9 5

1h 1h+ 330°C/1h 2h 2h+ 330°C/1h 3h 3h+ 330°C/1h 4h 4h+ 330°C/1h 6h 6h+ 330°C/1h 8h 8h+ 330°C/1h 10h 10h+ 330°C/1h 12h 12h+ 330°C/1h ss

90 91 92 93 94 95

2 θ (°)

Intensity (a.u.)

ss 1h 1h+330°C/1h 2h 2h+ 330°C/1h 3h 3h+330°C/1h 4h 4h+330°C/1h 6h 6h+330°C/1h 8h 8h+330°C/1h 10h 10h+330°C/1h 12h 12h+330°C/1h

Intensité (unit. arb.) 2 theta (degrés)

3 6 40 50 60 70 8 9

40 50 60 70 80 90

2 θ (°)

Intensity (a.u.)

Fe Fe Ni3Fe Ni

peaks shift to LOWER 2θ angles peaks shift to HIGHER 2θ angles broadening of the diffraction peaks

  • Ni3Fe phase formation
  • the first order internal stresses

relaxion of the first order internal stresses the second order internal stresses Crystallite size reduction

  • I. Chicinas et al. J. Alloys and Compounds 352 (2003), p. 34-40.

Improve the solid state reaction Release the internal stresses

Annealing effect

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 16

slide-40
SLIDE 40

88 90 92 94 9

Intensity (a.u.) 2 th e ta (d e g re e s)

8 8 9 9 2 9 4 9

Ni3Fe Ni

88 89 90 91 92 93 94 95 2 θ (°)

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h 14 h 16 h 20 h 24 h

as milled

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+300°C/30min

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h 14 h 16 h 20 h 24 h

+330°C/1h

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+330°C/3h +330°C/8h

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+330°C/12h

ss

Intensity (a.u.)

88 90 92 94 9

Intensity (a.u.) 2 th e ta (d e g re e s)

8 8 9 9 2 9 4 9

Ni3Fe Ni

88 89 90 91 92 93 94 95 2 θ (°)

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h 14 h 16 h 20 h 24 h

as milled

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h 14 h 16 h 20 h 24 h

as milled

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+300°C/30min

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+300°C/30min

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h 14 h 16 h 20 h 24 h

+330°C/1h

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h 14 h 16 h 20 h 24 h

+330°C/1h

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+330°C/3h

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+330°C/3h +330°C/8h

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+330°C/12h +330°C/8h

1 h 2 h 3 h 4 h 6 h 8 h 10 h 12 h

+330°C/12h

ss

Intensity (a.u.)

(311)

One annealing time - Different milling time

8 8 9 0 9 2 9 4 9

Intensity (a.u.) 2 th eta (de g ree s)

8 8 9 9 2 9 4 9

88 89 90 91 92 93 94 95 2 θ (°)

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 1 h

ss

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 2 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 3 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 4 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 6 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 8 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 10 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 12 h

0 h 1 h

milled 14 h

0 h 1 h

milled 16 h

0 h 1 h

milled 20 h

0 h 1 h

milled 24 h

Ni3Fe N i

Intensity (a.u.)

8 8 9 0 9 2 9 4 9

Intensity (a.u.) 2 th eta (de g ree s)

8 8 9 9 2 9 4 9

88 89 90 91 92 93 94 95 2 θ (°)

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 1 h

ss

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 2 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 3 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 4 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 6 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 8 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 10 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 12 h

0 h 1 h

milled 14 h

0 h 1 h

milled 16 h

0 h 1 h

milled 20 h

0 h 1 h

milled 24 h

8 8 9 0 9 2 9 4 9

Intensity (a.u.) 2 th eta (de g ree s)

8 8 9 9 2 9 4 9

88 89 90 91 92 93 94 95 2 θ (°)

8 8 9 0 9 2 9 4 9

Intensity (a.u.) 2 th eta (de g ree s)

8 8 9 9 2 9 4 9

88 89 90 91 92 93 94 95 2 θ (°)

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 1 h

ss

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 2 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 3 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 4 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 6 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 8 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 10 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 12 h

0 h 1 h

milled 14 h

0 h 1 h

milled 16 h

0 h 1 h

milled 20 h

0 h 1 h

milled 24 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 1 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 1 h

ss

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 2 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 2 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 3 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 3 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 4 h

0 h 0.5 h 1 h 2 h 3 h 12 h

milled 4 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 6 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 6 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 8 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 8 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 10 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 10 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 12 h

0 h 0.5 h 1 h 2 h 3 h 8 h

milled 12 h

0 h 1 h

milled 14 h

0 h 1 h

milled 14 h

0 h 1 h

milled 16 h

0 h 1 h

milled 16 h

0 h 1 h

milled 20 h

0 h 1 h

milled 20 h

0 h 1 h

milled 24 h

0 h 1 h

milled 24 h

Ni3Fe N i Ni3Fe N i

Intensity (a.u.)

One milling time - Different annealing time

Ni3Fe produced by MAAC

Mean grain size : 15 ± 2 nm , after 32 h milling European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 17

slide-41
SLIDE 41

3.8 3.9 4.0 4.1 4.2 4.3 4.4 0.5 1 1.5 2 2.5 3 3.5

M (µB/f.u.) annealing time (hours) T = 300 K

ss 1 h 2 h 3 h 4 h 6 h 8 h x 10 h

  • 12 h

4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 0.5 1 1.5 2 2.5 3 3.5

M (µ

B/f.u.)

annealing time(hours) T = 4 K

ss 1 h 2 h 3 h 4 h 6 h 8 h x 10 h

  • 12 h
  • V. Pop, O. Isnard and I. Chicinas,
  • J. Alloys and Comp., 361 (2003), p.144-152.

Ni3Fe produced by MAAC

Influence of the milling and annealing conditions on the Ms

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 18

slide-42
SLIDE 42

0h 3h 4h 8h 10h 12h

Velocity ( mm / s )

  • 10

+10 0.96 1.00 Absorption ( % ) 0.96 1.00 Absorption ( % ) 0.97 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.99 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % )

16h 24h 40h 48h 52h 52h annealed

Velocity ( mm / s )

  • 10

+10 0.99 1.00 Absorption ( % ) 0.99 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % )

Speed (mm/s)

  • 10 0 +10

Speed (mm/s)

  • 10 0 +10

Absorption (%) Absorption (%)

Mössbauer spectrometry Ni3Fe powders

  • I. Chicinas, V. Pop, O. Isnard, J.M. Le Breton and J. Juraszek, J. Alloys and Compounds 352 (2003), p. 34-40

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 19

slide-43
SLIDE 43

20 40 60 80 100 10 20 30 40 50 60

Intensité Mossbauer (%) Temps de broyage (h) Ni3Fe α-Fe

Mössbauer intensity (%) milling time (hours) 0h 3h 4h 8h 10h 12h

Velocity ( mm / s )

  • 10

+10 0.96 1.00 Absorption ( % ) 0.96 1.00 Absorption ( % ) 0.97 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.99 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % )

16h 24h 40h 48h 52h 52h annealed

Velocity ( mm / s )

  • 10

+10 0.99 1.00 Absorption ( % ) 0.99 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % ) 0.98 1.00 Absorption ( % )

Speed (mm/s)

  • 10 0 +10

Speed (mm/s)

  • 10 0 +10

Absorption (%) Absorption (%)

Mössbauer spectrometry Ni3Fe powders

  • I. Chicinas, V. Pop, O. Isnard, J.M. Le Breton and J. Juraszek, J. Alloys and Compounds 352 (2003), p. 34-40

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 19

slide-44
SLIDE 44

Nanocrystalline soft magnetic powders from Fe-Ni-X-(Y) systems

FeNi3)xAg1-x, Ni50Al50-xFex , Fe49Ni46Mo5, Fe42Ni40B18 , Ni-15%Fe-5%Mo and Ni-16%Fe-5%Mo (wt%), Ni-14%Fe-5%Cu- 4%Mo and others

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 20

slide-45
SLIDE 45

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min ss as milled Ni3Fe

800 700 600 500 400 300 200 100

40 50 60 70 80 90 100 110 2 Theta (°) Intensity (a.u.)

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min ss as milled Ni3Fe

800 700 600 500 400 300 200 100

40 50 60 70 80 90 100 110 2 Theta (°)

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min ss as milled Ni3Fe

800 700 600 500 400 300 200 100

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min ss as milled Ni3Fe 350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min ss as milled Ni3Fe 350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min ss as milled Ni3Fe 350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min ss as milled Ni3Fe

800 700 600 500 400 300 200 100

40 50 60 70 80 90 100 110 2 Theta (°) Intensity (a.u.)

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min as milled Ni3Fe ss

40 50 60 70 80 90 100 2 Theta (°)

800 700 600 500 400 300 200 100 Intensity (a.u.)

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min as milled Ni3Fe ss

40 50 60 70 80 90 100 2 Theta (°)

800 700 600 500 400 300 200 100

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min as milled Ni3Fe ss

40 50 60 70 80 90 100 2 Theta (°)

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min as milled Ni3Fe ss

40 50 60 70 80 90 100 2 Theta (°)

350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min as milled Ni3Fe ss 350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min as milled Ni3Fe ss 350 °C/4h 350 °C/2h 350 °C/1h 350 °C/ 30 min as milled Ni3Fe ss

40 50 60 70 80 90 100 2 Theta (°)

800 700 600 500 400 300 200 100 Intensity (a.u.)

8 hours milling 6 hours milling

θ β λ cos

2 1 ⋅

⋅ = k d

2 1

β - FWHM

d = 11 nm - 16 h milling and annealing at 350 °C for 2 hours in order to remove second order internal stresses

Supermalloy synthesis by MAAC:

  • 8 hours milling
  • different annealing conditions.
  • I. Chicinas, O. Isnard, V. Pop, J. Mater. Sci. 39 (2004), p. 5305-5308
  • O. Isnard, V. Pop, I. Chicinaş, J. Magn. Magn. Mater. 290-291 (2005), p. 1535-1538.

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 21

slide-46
SLIDE 46

300 500 700 900 1100

Temperature (K)

TC Ni

T

C NiFeCuMo

T

C Fe

Temperature (K) M² (a.u.) 10 h 4h ss A B

300 500 700 900 1100

Temperature (K)

TC Ni

T

C NiFeCuMo

T

C Fe

Temperature (K) M² (a.u.)

300 500 700 900 1100

Temperature (K)

TC Ni

T

C NiFeCuMo

T

C Fe

Temperature (K) M² (a.u.) 10 h 4h ss A B

Analyse thermomagnétique

SS : Mélange de départ Tc de Ni et Fe 4h : -Chauffage changement de pente au point A correspond à Tc de NiFeCuMo obtenu par broyage

  • Formation progressive de l’alliage

par chauffage (région B) Large domaine de composition

  • Refroidisement une seule Tc détectée

alliage formé dans le volume 10h : seule la Tc de l’alliage est observée le traitement thermique homogénéise

Alliage 77Ni14Fe5Cu4Mo % massique

Température en K

  • F. Popa, O. Isnard, I. Chicinas, V. Pop, J. Magn. Magn. Mater., 316 (2007) e900–e903

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 22

slide-47
SLIDE 47
  • O. Isnard, V. Pop, I. Chicinaş,
  • J. Magn. Magn. Mater. 290-291 (2005) 1535
  • Y. Shen, H.H. Hng, J.T. Oh,
  • J. Alloys Comp. 379 (2003) 266-271.

the mechanical alloying process

  • ccurs in two steps

an intermediate amorphous or poorly crystallined phase, (Ni,Fe)–Mo type. The high coercivity before 10 h of milling is attributed to strong pinning of domain walls of the interaction domains at the grain boundaries. European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 23

slide-48
SLIDE 48

The Ni, Fe and Mo maps on starting sample (0 hours milling) and on the 12 hours milled sample. It can observe the chemical homogeneity of the Supermalloy powders obtained by mechanical alloying and the particles morphology, too.

Ni particles Fe particles Mo particles

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 24

slide-49
SLIDE 49

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 25

FAPAS Field activated pressure assisted sintering. Compared to a classical sintering process under pressure, a current is applied in order to assist the sintering. A current exhibiting a high intensity (up to 8,000 A) under low voltage (10 V) is applied.

Methods to produce from the nanocrystalline powders a a nanocrystalline compact

  • E. Gaffet, G. Le Caër, Mechanical Processing for Nanomaterials, in Encyclopaedia of

Nanoscience and Nanotechnology, vol.X, Ed. by H.S. Nalwa, American Sci. Publishers (2004).

slide-50
SLIDE 50

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 26

Spark plasma sintering A process leading to bulk materials by a sintering step using pulse electric discharge. Due to the high intensity of the current, plasma may occur between the various powder grains.

Methods to produce from the nanocrystalline powders a a nanocrystalline compact

  • V. Mamedov, Powder Metallurgy 2002 Vol. 45 No. 4, 322-327
slide-51
SLIDE 51

Soft magnetic nanocrystalline composites

Ni3Fe

polymer layer

+

polymer dissolving

Ni3Fe

nano covered powder (1, 1.5, 2, 3 wt%)

Die pressed

(600 - 800 MPa )

Polymerisation

(60 min., 180 oC)

Composites Production

  • I. Chicinaş, O. Isnard, O. Geoffroy, V. Pop, J. Magn. Magn. Mater. 310 (2007), 2474-2476

16 18 20 22 24 26 28 30 100 200 300 400 500 600 20 40 60 80 100

µ; Ni3Fe; B=0.05 T µ; NiFe; B=0.05 T µ; Ni3Fe; B=0.1T µ; NiFe; B=0.1T µ; Ni3Fe; B=0.2T µ; NiFe; B=0.2T P/f; Ni3Fe; B=0.05 T P/f; NiFe; B=0.05 T P/f; Ni3Fe; B=0.1 T P/f; NiFe; B=0.1 T P/f; Ni3Fe; B=0.2 T P/f; NiFe; B=0.2 T

µ P/f (J/m3) f (kHz)

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 27

slide-52
SLIDE 52

Conclussions

The possibility of producing chemical transformations through mechanical energy has been extensively demonstrated in metallic as well as in oxide systems The nanocrystalline/nanosized powders obtained by different mechanical routes exhibit very interesting properties, some from them different from those of bulk materials

European School of Magnetism, Cluj-Napoca, 9-18 Sept. 2007, 28

slide-53
SLIDE 53

Thank you for your attention!