CH MaD

Use Cases: Inorganic Systems

G. B. Olson

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Cohen’s Reciprocity

Cohen’s Reciprocity

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System chart

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Hierarchy of Design Models

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Example: Parametric Design with CMD Matrix  +  Strengthening  Dispersion  Design  

Grain  Pinning  Dispersion  Design  

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Hard Material Use-Case Groups

•  Cobalt alloys •  Nanodispersion-strengthened shape

memory alloys •  Si-based insitu composites •  Leveraging: Steel Research Group

projects

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Cobalt Alloy Designs G. Olson (NU), D. Dunand (NU), D. Seidman (NU), P. Voorhees (NU),

M. Stan (NAISE, ANL) C. Wolverton (NU)

•  Motivation: –  Need turbine blade alloys that exceed

the use temperatures of Ni-based superalloys

–  Wear resistant ambient temperature applications to replace Be-Cu

•  Goals: –  Near-term: Ambient temperature

bushing alloy –  Long-term: High-temperature

aeroturbine superalloy

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PH Cobalt System Chart

VIM/VAR melting

Homogen-ization

Hot working >4” dia.

Solution treatment

Machining

Tempering

Processing Structure

Solidification structure

- Inclusions- Eutectic

Grain Structure- Grain size- GB chemistry- pinning particles- Avoid cellular reaction

Nanostructure- Low-misfit L12- Size & fraction- Avoid embrittlingphases

Matrix- FCC (avoid HCP transformation)- Low SFE- Solid solution strengthening

Properties

Non-toxic

Strength-120 to 180 ksicompressive YS- CW not required for strength

Wear- Low CoF- Galling/fretting resistance

Toughness-Highly ductile after solution treat- High toughness fully hardened

Corrosion Resistant

Environmentally Friendly

Bearing Strength

Wear Resistance

Damage Tolerant

Formable

Performance

Corrosion Resistant

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700C

γ γ’

B2

Laves

L12 Stability in Ni vs Co Systems

Ni

Co

γ γ’

B2

Liq.

γ

Liq.

η B2

γ γ’

η

B2

700C

Ni-Al Ni-Ti Ni-Al-Ti

Co-Ti Co-Al Co-Ti-Al

Liq.

γ γ’

B2 Laves

γ

Liq.

B2

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CALPHAD Step Diagram

γ' γ

L

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Validation of design with LEAP characterization LEAP validation of alloy nanostructure after tempering at ~780°C:

FCC (Co-rich) matrix and γ’ [L12 crystal structure, (Co,Ni)3(Ti,V)-type] strengthening nanoprecipitates

• Precipitate is enhanced in Co, Ti; slightly enhanced in Ni, V

• Matrix is enhanced in Fe, Cr

Matrix

Precipitate is enhanced in Co, Ti;

slightly enhanced in Ni, V

Matrix is enhanced in Fe, Cr

Precipitate

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Approach •  Years 1 and 2:

–  Accelerated expansion of Co system multicomponent solution thermodynamics, molar volume, and diffusivity databases (high throughput theory and experiment) to incorporate Nb, Mo, Ta, Re and B for FCC, L12 and L phases.

–  LEAP microanalytical calibration and validation. •  Years 3 and 4

–  Prototype alloy validation and preliminary process optimization

–  PrecipiCalc calibration and application to detailed process optimization

–  Solidification and homogenization modeling for scale-up –  Continuum modeling of creep deformation dynamics –  Neutron and X-ray diffraction evaluation of load

partitioning

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G. Olson (NU), D. Dunand (NU),W-K. Liu (NU) D. Seidman (NU),

A. Umantsev (FS), C. Wolverton (NU)

Nanodispersion-­‐Strengthened  Shape  Memory  Alloys  

•  Motivation: –  Widely used in medical, aerospace and

automotive sectors –  Current alloys are susceptible to

instability after many cycles

•  Goals: –  Near-term: Pd-stabilized alloys for

medical devices –  Long-term: High-temperature

aeroturbine & automotive actuators

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Processing

Aging

Solution treatment

Hot working

Properties

Strength

Af Temperature

Transformation Range (ΔTR=Af-As)

Hysteresis (ΔTH=Af-Ms)

Toughness Ductility

Structure

Nanodispersion (Ni,Pd,Pt)2 (Ti,Zr,Hf) Al

Heusler Phase Low Misfit

Dispersion Particle Size Volume Fraction

B2 Matrix (Ni,Pd,Pt) (Ti,Zr,Hf,Al)

Al (Substitution for Ti)

Zr/Hf (Substitution for Ti)

Performance

Longer Cyclic Life

Operating Temperature

Faster Response

Higher Output Stress

Grain refining oxides Arc-melting Ti4Ni2O, Y2O3

Pd/Pt (Substitution for Ni)

Powder Consolidation

SMA System Chart

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20nm

1hr 3.5hr 7.5hr 16hr 50hr

0.0 1 10 1000.0

2

4

6

Particle Radius(nm)

Ageing time at 550C(hr)

1023

1024

1025

NumberDensity (m-3)

0

2

4

6

8

10

Phase fraction(%)

0 2 4 6 8 10

0

200

400

600

800

1000

1200

1400

1600

1800

Δσ/f1/

2

Precipitate radius (nm)

Precipitation strengthening in (Pd,Ni)50(Ti,Al)50 alloys

Ageing at 550°C

Optimal particle radius=2.3nm

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0

350

0 0.018StrainS

tress

(MP

a)0

1200

0 0.06Strain

Stre

ss (M

Pa)

-0.4

0.4

-50 -30 -10 10Temperature (C)

Hea

t Flo

w (W

/g)

SMA  Cyclic  Stability  

-0.16

0.16

-55 -35 -15 5 25Temperature (°C)

Hea

t Flo

w (W

/g)

hea4ng  

cooling  

hea4ng  

cooling  

Af  +  25°  

Yield  stress  and  hysteresis  width  decrease  and  permanent  elonga4on  increases  

Nemat-­‐Nasser2006  

Thermal    cyclic  stability  

Mechanical    cyclic  stability  (compression)  

Af  +  63°  

Ti49.3Ni50.8  Ni20Pd30Ti46Al4  

 

Aged  600°C,  5h  

N=5  

0.6%  permanent  set  

N=6  

<  0.2%  permanent  set  

1  4   2  3  

1  4   2  3  

30  cycles  

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TiNi Fatigue Life Prediction: Effect of Increased B2 Strength

Increased life (N) of strengthened alloy compared typical life (No)

•  50% increase in matrix strength results in increase in fatigue limit (at 109 cycles) from 0.27% to 0.39%

•  Benefit of B2 strengthening increases as applied strain decrease

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Approach

•  Years 1 and 2: –  Accelerated expansion of solution thermodynamics, molar

volume, and diffusivity database (high throughput theory and experiment) of Ti-Zr-Hf-Ni-Pd-Pt-Fe-Co-Ni-Al-O-C system for B2, L21, M(O,C), M6O, and martensitic phases

–  LEAP microanalysis calibration and validation –  D3D characterization of fatigue nucleants and ABC continuum

modeling of fatigue nucleation

•  Years 3 and 4 –  Prototype evaluation and preliminary process optimization –  PrecipiCalc calibration and application to process optimization –  ABC continuum modeling of oxide and carbide evolution during

deformation processing –  Solidification and homogenization modeling for process scale-up

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In-Situ Si Composite Materials P. Voorhees (NU), J. De Pablo (UC), W. Chen (NU),

S. Davis (NU) , C. Wolverton (NU)

Si-CrSi2 composite (Fischer and Schuh, J. Am Ceram. Soc, 2012)

•  Motivation: –  Corrosion resistant, tough alloys –  Avoid the complications of

classical ceramic processing, such as sintering

–  Employ insitu Si-composites

•  Goals: –  Near-term: A multicomponent

eutectic growth model –  Long-term: A tough, castable Si

alloy

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Design Approach

•  Primary mechanism of toughening is the delamination of interphase interfaces

•  Composites are produced via eutectic solidification •  Industrial partner: Dow Corning

Processing Structure Properties

Melting

Eutectic solidificat

ion

Thermal treatmen

t

CrSi2 reinforcement

Si matrix

Matrix / reinforcement

interface

Toughness

Strength

Corrosion resistance

Performance

Castable

Strength in compressio

n

Wear resistance

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Growth of Si Composites

Due to the anisotropy of the solid-liquid interfacial energy, Si alloys can grow as irregular eutectics

Isotropic Anisotropic

Al-Si

L L

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Approach

•  Years 1 and 2: –  Use multicomponent thermodynamics to inform eutectic growth

models –  Generalize eutectic growth models to multicomponent systems,

use existing corrections for anisotropic interfacial energy –  Predict solidification paths, and thus volume fractions of phases,

and length scales of the solidified morphologies •  Years 3 and 4

–  Phase field models for systems with highly anisotropic solid-liquid interfacial energy

–  Develop descriptors of the microstructure –  Using these descriptors, and models of the toughening process,

design optimal microstructures –  Using models for the multicomponent eutectic solidification

process develop optimal microstructures –  Characterization using X-ray tomography

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2014 SRG Design Projects

•  ONR Cyberalloys (Olson, Freeman) - CMD of Fe & Ti alloys for blast and fragment protection •  DOE/GM Lightweighting Initiative (Olson, Wolverton,

Voorhees) - CMD of cast aluminum for cylinder heads •  DOE/CAT Lightweighting Initiative (Olson, Liu) - CMD of cast steels for crankshafts •  ArcelorMittal AHSS (Olson) - CMD of high-strength automotive Q&P TRIP steels •  NIST/NIU MSAM Additive Manufacturing (Olson, Liu, Cao) - CMD of Fe & Ti alloys for additive manufacturing DARPA/Honeywell Open Manufacturing (QuesTek) - ICME for SLM additive manufacturing of Ni 718+