arpa-e hitemmp annual program review designing fabricable

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Designing Fabricable Alloys

for High Temperature Service

ARPA-E HITEMMP Annual Program Review

Drs. John Foltz, Reza Sharghi, Matias Garcia

ATI Specialty Materials

10/22/2020


Net-Shape Products & Components

ARPA-E Annual Meeting 2

Net-Shape Products

Powder Metal Alloys &

Near-Net Shapes

Net-Shape Machining

Machining - Near-Net

Components

Net-Shape Components

Forgings – Ti-, Ni-, Fe-

alloys

Additive Manufactured

Components – Laser

& EB powder bed

Machined Components:

Ti-, Ni-, Fe-, Al-, Mg-,

and Zr-alloys

Flowform - Shaft &

Drill Collars


5Operations in the

Midwest Region

6Operations in the

Western Region

7Operations in the

Southern Region

17Operations in the

Northeastern

Region

Coon Valley, WI

Cudahy, WI

Appleton, WI

Bridgeview, IL

Louisville, OH

Richland, WA

Albany, OR

Millersburg, OR

Salem, OR

Irvine, CA

Pico Rivera, CA

Pittsburgh, PA

(ATI Headquarters)

Brackenridge, PA

Latrobe, PA

Monaca, PA

Natrona Heights, PA

Oakdale, PA

Robinson, PA

Rochester, PA

Vandergrift, PA

Washington, PA

Zelienople, PA

Billerica, MA

New Bedford, MA

East Hartford, CT

Waterbury, CT

Lockport, NY

Arlington, VA

Manufacturing / Research

& Development

Service Centers

Sales Offices

US Locations

Bakers North, NC

Bakers South, NC

Bakers Powder, NC

Monroe, NC

Richburg, SC

Huntsville, AL

Houston, TX



Future

Industry

Needs

Design to

achieve target

microstructure

Pilot scale trials

Full Scale

Trials in a

Production

Environment

Courtesy of ASM International

Beta

Alpha

Third Phase

evaluate

analyzetest

improve

ATI R&D Approach to New Product Development

4ARPA-E Annual Meeting


Pilot Scale Equipment


VIM Furnace Open Die Press Remelt Furnace

Rolling Mill

AM / PM equipment:• Lab- and Pilot-scale atomization

• Lab-scale HIP

• Lab-scale LPBF

Characterization equipment:

• Chemistry Lab

• Metallographic Lab

• SEM with advanced capability

• Mechanical Test Lab


Heat Exchanger Materials for Extreme Environments



Alloy for extreme environments

in an advanced heat exchanger

• 1500°F (815°C) capable for 40,000 hours o Stretch Goal: 1800°F (1000°C)

• High thermal conductivity, low CTE

• Microstructural stability over service life

• Evaluated on mechanical propertieso Internal pressure ≥ 80 bar

o Improved tensile and creep strength

over historic alloys

o Resistant to all forms of fatigue

• Corrosion & oxidation resistant

• Printable

o Weldable and low susceptibility to strain-age cracking

o Capable of thin wall AM

o Ideally rollable for ancillary components

HITEMMP Critical to Quality (CTQ) Requirements

Available manufacturing routes

• AM-3D printing

• Cast/wrought alloy (Rolling/welding sheet metal)

• Mechanical Alloying

3D printed a heat exchanger for more efficient

energy conversion [1]



Candidate Materials Properties and Performance


a) MPEAs

b) HEAs

Strengthening

MechanismProperties and performance

MFG CL CH MS TH

Ni Base Superalloys

γ/γ′

strengthened/ +++ +++ + +++ René 41

Haynes 282

Waspaloy

γ/γ″

strengthened+ ++ - - - - - - Alloy 718

Solid solution/carbide

strengthened ++ +++ + ++ / Alloy 617

Haynes 230

Alloy 625

High Entropy Alloys

MPEAs / CCAs -

- -

Unk. Unk. Unk. ++

Fe-Ni-Cr-Mn-Mo

Fe-Ni-Cr-Al

HEAs

Ni-Co alloys γ′ strengthened ++ ++ + + +

Other possible

systems

Composite, ceramic - Unk. +++ +++ - -

MFG: Manufacturability

CL: Creep at low stress intermediate temperature

CH: Creep at low stress high temperature

MS: Microstructural stability

TH: Tensile strength at high temperature

+++ Excellent

++ Very Good

+ Good

/ Fair

- Poor

- - Very Poor



Material and Process Design Experience for AM

Going beyond commercially available materials…

New Nickel Base

Superalloys Niobium Alloys

Higher Temperature

Capability

Status

Benefits

New Titanium

Alloys Copper Alloys

Higher Strength High Thermal

Conductivity

Sustained High

Temperature

CapabilityLess Distortion

Under DevelopmentAvailable in Powder

and Parts

Available in

Powder and

Parts

Available in Powder and

Parts

ATI Titan Alloys ATI C103 Alloy ATI GRCop Alloys

Additive Equipment• Multiple PBF machines at

various size scales

Materials Experience • Titanium

• Nickel

• Aluminum

• Niobium

• Stainless Steel / Iron-based


Evaluation of LPBF manufacturability of γ/γ′ alloy


Printed bars for mechanical tests

Haynes 282 for HITEMMP

• Two DOEs conducted to date

• Achieved >99.9% build density

• Conducting mechanical tests

Discussed in greater detail

yesterday by Dr. Yousefiani

HITEMMP shares many CTQs

with turbine engine cases


1500°F Case Alloy




Required CTQs for 1500°F Cases

o Low Cycle Fatigue

• Critical for design

• Driven by chemistry, strength, grain size

and cleanness

o Fracture toughness/FCGR

• Required for CDN and some HPT cases

• Kc and FCGR important but not at the

expense of LCF and Creep

o Long Term Phase Stability

• No TCPs, and acceptable

coarsening

o Forgeability

• Ring rolling capability

o Weldability

• Repair and maintenance

o NDT Inspectability

Property Test conditions Requirements

Tensile

Room temp Waspaloy + 100°F

1500°FYS = 100 ksiUTS = 120 ksiElongation = 15+%

LCF 1500°F / 0.50% SR 80,000 cycles

Weldability Comparable to Waspaloy

Test Matrix for 1500°F Cases

Typical Gas Turbine Casing [2]



CALPHAD Based Modelling Tools

Predicting stability of γ′ phase to design forging practice

Predicting sigma phase formation and design

heat treatments to avoid them

Phase prediction for each designed chemistry

Phase(%

)

• Alloy design consideredo Hot working

o Heat treatment response

o Microstructural phases and stability

• Used modeling to accelerate processo CALPHAD for microstructure

o FEA for TMP

o Recognizing model limitations


Pilot Plant VIM Melting

14

25 lb VIM molds As-cast microstructure

14 different chemistries were selected in above chemistry space for 25lbVIM melting in pilot plant

Cr Co Ti Al Nb W Mo Ta Hf Ni

>12 14-28 2.5-6.5 1-3 < 2 0-5 0-10 < 2 0-2 Bal

Chemical composition space to design new alloy(wt%)

ARPA-E Annual Meeting


Pilot Plant Press Forging

15

Optical microstructure as-forged

Ingot before and after thermomechanical work

As-cast

Forged

Thermomechanical work in pilot plant

25 μm

Thermomechanical simulation to

optimize parameters



16

MIPAR image quantification of γ′

volume fraction after heat treatment

γ′= 32 %

Heat Treatment Design

Super-solvus heat treatment to

obtain unimodal γ′ distribution

Formation of η-phase (Ni3Ti) occurs in

suboptimal chemistries or heat treatment


EDS map shows carbide distribution at grain

boundaries to improve mechanical properties

η-phase

1 μm 10 μm


Super-Solvus Heat Treatment Response


Grain size distribution after super

solvus heat treatment

Grain growth in super-solvus heat

treatment was observed

Grain size distribution in as-

forged condition



Uniform and unimodal distribution of

γ′ precipitates after super-solvus

heat treatment

Microstructure of stress ruptured

sample at 40ksi/1500F after 1000 hrs.

Slight coarsening of γ′, and no new

phases

Aging Heat Treatment Response

5 μm 5 μm



Yield stress of selected chemistries at

various temperatures.

Improved strength at 1500°F over both

Waspaloy [3] and Haynes 282 [4]

Mechanical Properties

Stress rupture properties shows

better performance for designed

chemistries

1500°F70°F


Conclusion


• High temperature materials balance many competing

properties, for both heat exchangers and cases

applications

• Many case alloys showed very good pilot-scale capabilityo Some demonstrated very good forgeability

o Improved tensile and stress rupture behavior

o No deleterious phases observed in the microstructure

o Only slight coarsening of γ′ observed after

1000hrs exposure at 1500°F

[1]: 3D Natives, April 24, 2019

[2] International Journal of Mechanical and Production Engineering, Vol.5, May 2017

[3] Waspaloy Data: https://www.specialmetals.com/assets/smc/documents/alloys/other/waspaloy.pdf

[4] Haynes 282 Data: https://www.haynesintl.com/alloys/technical-literature-list

https://www.specialmetals.com/assets/smc/documents/alloys/other/waspaloy.pdf

https://www.haynesintl.com/alloys/technical-literature-list


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21ARPA-E Annual Meeting

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