From grains to atoms: ping-pong between experiment

and simulation for understanding microstructure mechanisms

Düsseldorf, Germany

P.-P. Choi, M. Kuzmina, J. Deges, M.J. Yao, O. Cojocaru-Miredin, I. Povstugar, C. Liebscher, M. Lipinska-Chwalek, S. Katnagallu,

D. Ponge, M. Herbig, C. Tasan, A. Stoffers, S. Sandlöbes, T. Hickel, J. Neugebauer, J. Mayer, C. Scheu, G. Eggeler, D. Raabe

Dierk Raabe, Res Metallica Symposium, Department of Materials Engineering, KU Leuven, May11th 2016

1

Zeitalter tragen die Namen von Materialien

Experiment

Models

2

Complex materials: atomic scale view

Atom Probe:

Imaging

atoms

Solar Cells High

temperature

materials

Strong light-

weight

steels

3

Complex materials: atomic scale view

Atom Probe:

Imaging

atoms

Solar Cells High

temperature

materials

Strong light-

weight

steels

Atom Probe Tomography (APT)

4

Ion sequence Position sensitive detector

X1, Y1, ToF1

VDC

Vp + Time of flight

X2, Y2, ToF2

X3, Y3, ToF3

X4, Y4, ToF4

R 50 nm

T 20–100 K

X5, Y5, ToF5

……..

Time of flight chemical identity

Position of hit X-Y coordinates

Evaporation sequence Z coordinate

or

The specimen is the lens

3D point cloud data

Atom Probe Tomography (APT): directions for structure resolution

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can you get structure?

It‘s a point cloud

approach 1: use evaporation anisotropy

approach 2: combine APT withTEM / SEM / STEM

Guo et al phys rev let. 2014, Duarte et al. Science 341, 372 (2013)

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Atom Probe Tomography (APT): evaporation anisotropy

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Atom Probe Tomography (APT): evaporation anisotropy

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Atom Probe Tomography (APT): evaporation anisotropy

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Atom Probe Tomography (APT): evaporation anisotropy

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(002) planes

Atom Probe Tomography (APT): evaporation anisotropy

11

(111) planes

Atom Probe Tomography (APT): evaporation anisotropy

12

(001) (012)

(113)

(112)

(111)

(011)

Field desorption image; example Fe3Al

12 Herbig et al., phys rev let. 2014, Guo et al phys rev let. 2014

[111]

[-1

-12

]

0.33 nm 0.25 nm

Lattice plane reconstruction: APT crystallography

Fe3Al (only Al displayed)

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Atom probe crystallography:

Chemistry and structure in 3D

Kuzmina et al. Science 349 (2015)

2 nm

[111]

[-1

-12

]

0.33 nm 0.25 nm

Lattice plane reconstruction: APT crystallography

Fe3Al (only Al displayed)

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Atom probe crystallography:

Chemistry and structure in 3D

Kuzmina et al. Science 349 (2015)

Experimental setup for correlative TEM–APT probing

Ga3+

52°

modified single-

tilt TEM retainer

sample

FIB: Tip is cut parallel to

holder axis.

e-

TEM: During tilt around

holder axis tip always stays

in focus range, whole

sample in focus (!).

Ions

APT: Defined sample orientation

in all instruments makes it

possible to merge information.

Principle

Guo et al phys rev let. 2014, Duarte et al. Science 341, 372 (2013) 15

Li et al. phys rev let. 2014 Herbig et al., phys rev let. 2014

Experimental setup for correlative TEM–APT probing

Ga3+

52°

modified single-

tilt TEM retainer

sample

FIB: Tip is cut parallel to

holder axis.

e-

TEM: During tilt around

holder axis tip always stays

in focus range, whole

sample in focus (!).

Ions

APT: Defined sample orientation

in all instruments makes it

possible to merge information.

Principle

Guo et al phys rev let. 2014, Duarte et al. Science 341, 372 (2013) 16

Li et al. phys rev let. 2014 Herbig et al., phys rev let. 2014

Correlative TEM-APT probe for 5D GB segregation analysis

BF-STEM micrograph of cold-drawn Fe-C

(010) (00-1)

(-100)

e- beam

Nano beam diffraction

Scanning nano beam diffraction

100 nm

(ASTAR)

Acta Mat 61 (2013) 3172, Herbig et al. phys rev let. 2014 17

Carbon atoms

50 nm

18

Correlative TEM-APT probe for 5D GB segregation analysis

5 crystal. parameters

N chemical species

Herbig phys rev let., (2014); Kuzmina et al. Science 349 (2015) Li. phys rev. let (2014)

• Mn

• Fe

Mn 11 at% isosurface

Segregation at dislocation lines (ε=50% & 450°C/6h): Fe-9wt% Mn

19 Kuzmina et al. Science 349 (2015) Li. phys rev. let (2014)

Correlated microscopy LAGB (50%CR+450°C/6h) Fe-9%Mn

20

• Mn

• Fe

Mn 11 at% isosurface

Kuzmina et al. Science 349 (2015) Li. phys rev. let (2014)

• Mn

• Fe

Mn 11 at% isosurface

Segregation at dislocation lines (ε=50% & 450°C/6h): Fe-9wt% Mn

21 Fe-Mn: segregation & reversion: trends for middle Mn steels

22

Complex materials: atomic scale view

Atom Probe:

Imaging

atoms

Solar Cells High

temperature

materials

Strong light-

weight

steels

23 Courtesy: Siemens

New materials for key energy technologies: Turbine materials

s

Source: Siemens

75% energy conversion

via turbines

<44% efficiency

24 Courtesy: Siemens

New materials for key energy technologies: Turbine materials

Source: Siemens

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Example: 4th generation superalloys for turbine blades (SFB / TR 103)

20 nm

Al

Co

Re

iso. 56 at.% Ni

source GE

26

Complex materials: atomic scale view

Atom Probe:

Imaging

atoms

Solar Cells High

temperature

materials

Strong light-

weight

steels

27 Courtesy: Maybach, Siemens, ThyssenKrupp, VW, IG Metall Eng.

New materials for key energy technologies: Mobility

courtesy: R. Boesenkool, SMEA conference, Sheffield

SUV sales, Germany

28 Nanostructured Fe-based superalloy

Fe-30%Mn-8%Al-1.2%C – 10-18% Weight reduction

[100]/κ

[010]/κ

[001]/κ

HAADF-STEM 20nm

Characterizing Fe-Mn-Al-C /κ steel by correlative HRSTEM / APT

Al

Mn/Fe

C

DFT supercell of κ-carbide

courtesy: P. Dey, T. Hickel

APT

C 9.0 at.%

HRSTEM

2D structural analysis with

atomic resolution

- Coherency

- Lattice parameter

gradient

- Site occupancy

- Interface structure

APT

3D chemical analysis with near

atomic resolution

- 3D morphology

- Elemental partitioning

- Chemical gradients

29 Nanostructured Fe-based superalloy

30

Fe-30%Mn-8%Al-1.2%C – 10-18% Weight reduction

SiO2 pattern

1µm

Strain map

Experiments

Spectral solver Digital model Strain map &

stress map

Simulations

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ICME applied to dual phase steel

Integrated Computational Materials Engineering: DP steel

Deformation Imaging & DIC Sectioning

Indents

Martensite: Hierarchical microstructure analysis

Integrated Computational Materials Engineering: DP steel

Morsdorf et al. Acta Mater 95 (2015) 366

32

C

33 Integrated Computational Materials Engineering: DP steel

In-situ tensile testing: role of coarse lath in martensite fracture

SEM – in-situ tensile

Damage statistics in dual phase steels

34 Integrated Computational Materials Engineering: DP steel

DM: martensite damage; DM-F: martensite-ferrite decohesion

Tasan et al. Annu. Rev. Mater. Res.45 (2015) 391

35 DAMASK.mpie.de

Düsseldorf Advanced MAterial Simulation Kit, DAMASK

> 15 years of development

> 50 man years of expertise

> 50.000 lines of code

Pre- and post-processing

Blends with MSC.Marc and Abaqus

Standalone (FFT) spectral solver

Freeware, GPL 3

Crystal plasticity & phase field:

Mechanics, damage, phase transformation, diffusion

http://DAMASK.mpie.de

Many user groups

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Atom Probe:

Imaging

atoms

Solar Cells High

temperature

materials

Strong light-

weight

steels

Complex materials: atomic scale view

Σ3 with steps and high EBIC contrast

37 A. Stoffers, PRL, in press

Si

C

O 20 nm

Σ3 facets in HR-STEM

38

5 nm 2 nm

APT reconstruction LEAP 5000

39 Stoffers et al, 2015 PRL

Si

C

nm

Example Turbines

Example LED

Example Soft magnetic materials

Example Thin film solar cells

Example Hydrogen based energy

Example Catalysis

* All examples by current PIs except catalysis example which is by P. Bagot, Oxford

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Message & Conclusions

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The Düsseldorf Max-Planck Team

www.mpie.de