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MFS CSO 90714 Dr. Mark F. Smith Cold Spray Workshop Albuquerque, NM July 14-15, 1999 Overview of Cold Spray Particle Velocity (m/s) > 325 > 350 > 375 > 400 > 450 > 475 > 500 > 425 200 0 100 300 400 500 Gas Pressure (psig) 200 250 300 350 400 Gas Temperature (ˆC) Air, 22 μm Copper 100 μm

Overview of Cold Spray - Sandia National Laboratories · 2007-08-27 · MFS CSO 90714 250 m/s Cu A “Cold” Process Technology from Siberia 900 m/s Cu Deposition Efficiency Copper

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Text of Overview of Cold Spray - Sandia National Laboratories · 2007-08-27 · MFS CSO 90714 250 m/s Cu A...

  • MFS CSO 90714

    Dr. Mark F. SmithCold Spray Workshop

    Albuquerque, NMJuly 14-15, 1999

    Overview of Cold Spray

    ParticleVelocity (m/s)

    > 325

    > 350

    > 375

    > 400

    > 450

    > 475

    > 500

    > 425

    2000 100 300 400 500

    Gas

    Pre

    ssu

    re (

    psi

    g)

    200

    250

    300

    350

    400

    Gas Temperature (ˆC)

    Air, 22 µm Copper

    100 µm

  • MFS CSO 90714

    250 m/s Cu

    A “Cold” Process Technologyfrom Siberia

    900 m/s Cu

    Deposition Efficiency

    CopperCoating Material

    Iron Nickel Aluminum

    After Alkimov, et al , 1990

    400 500 600 700 800 900 1,000

    0.80.70.60.50.40.30.20.1

    0

    Particle Velocity m/s

  • MFS CSO 90714

    Sandia Cold Spray System

    HEATED GASGasInlets

    Heater

    TC

    Gas Heater

    PowderFeed

    RobotManipulator

  • MFS CSO 90714

    Spray Ductile Metals, Cermets, Polymers

    Active Braze Alloy AluminumAluminum BronzeCopper304 Stainless Steel420 Stainless Steel

    Fe3Pt MolybdenumMonel80Ni/20CrNiCrAlYNiCr-Cr3C2

    Polymer StelCarTantalumTinTitaniumWC-Co (nanophase)

    Examples of Materials Successfully Deposited at Sandia

  • MFS CSO 90714

    Cold Spray vs. Air Plasma Spray

    Plasma Sprayed Copper

    Cold Sprayed Copper

    100 µm

    100 µm

    • Superior Density• Less Oxide

  • MFS CSO 90714

    Some Exciting New Possibilities

    • Avoid melting & solidification- Avoid thermally induced stress- Avoid undesirable phases- Avoid oxidation (deposit metals in ambient air!)- Preserve desired phases & chemistry- Preserve original grain size (nanocrystalline mat’ls)

    • Low Porosity (>99% dense, as deposited)• High thermal / electrical conductivity (>80% OFHC Cu)

    • High Deposition Efficiencies (>98%)

    • Recycle feedstock & process gas• Work with highly dissimilar materials combinations

  • MFS CSO 90714

    New Possibilities, cont’d.

    • Highly wrought material (high hardness / strength)

    • Potential for high deposition rates• Relatively insensitive to standoff, work up close (

  • MFS CSO 90714

    Cold Spray Direct Fabrication

    • Additively build net / near-net shapes directly from a computer

    • Key technical challenge is focussing the spray stream

    ~ 1 mm FocusedStream for

    Subsonic Flow

    Do you want a print or a part?Print Build OK

    OK

    Do you want a Print or a Part?PrintBuild

  • MFS CSO 90714

    Example Applications

    • Anti-corrosion (superior density, less oxide)

    • Wear resistance (superior hardness & density)

    • Metals on ceramics / glass

    • High-alloy / specialty metals (preserve composition & phases)

    • Plastic coatings without volatile organics

    • Defect repair (minimal masking / heating, machinable)

    • Direct fabrication

    • Satellite structures (high conductivity, low residual stress)

  • MFS CSO 90714

    Reclaiming Parts & $$$

    Unusable $150k GPSsatellite part reclaimed

    with Cold Spray

    • Low heat input• Low stress• Dense, machinable• High conductivity,

  • MFS CSO 90714

    State of the Art

    • Technology ~ 10 years old• Success with many metals, some cermets & polymers• New materials / processing / manufacturing possibilities • Considerable industrial interest• Patented, but licenses available• No commercial use yet

  • MFS CSO 90714

    Barriers to Commercial Use

    Technical Issues:

    • Process fundamentals poorly understood• Cannot predict materials / parameters• Reduce / eliminate expensive helium• Nozzle fouling / optimization

    Build-up in nozzle

  • MFS CSO 90714

    Barriers to Commercial Use

    Manufacturing Issues:

    • No commercial equipment / coating suppliers• Need articulated robot compatible spray gun• Lack of property data / field experience• Need better fine powder feeders

    Uneven deposition dueto uneven powder feed

  • MFS CSO 90714

    Understanding Critical Velocity

    Raw Particle Velocity Distributions

    0

    20

    40

    60

    80

    100

    200 400 600 800 1000 1200

    0 %53 %95 %

    No

    rmal

    ized

    Co

    un

    ts

    Particle Velocity (m/s)

    DepositionEfficiency

    1 2 3

    19 µm Copper powder onto Aluminum

    0

    20

    40

    60

    80

    100

    450 500 550 600 650 700 750 800

    Dep

    osi

    tio

    n E

    ffic

    ien

    cy (

    %)

    Mean Particle Velocity (m/s)

    3

    2

    11

    2

    3ExperimentPrediction

  • MFS CSO 90714

    Process Maps Guide Optimization

    ParticleVelocity (m/s)

    > 325

    > 350

    > 375

    > 400

    > 450

    > 475

    > 500

    > 425

    2000 100 300 400 500

    Gas

    Pre

    ssu

    re (

    psi

    g)

    200

    250

    300

    350

    400

    *DV�7HPSHUDWXUH��Û&�

    Air, 22 µm Copper

  • MFS CSO 90714

    Models Guide Nozzle Design

    dDdP

    = CD ApM 2

    2− 1

    dVpdt

    = Dm

    Vp = particle VelocityD = Drag forcem = particle MassP = Pr essure

    CD = Drag coefficientAp = Area of particleM = Mach number

    max @ M = 2 = 1.4

    (air)

    (helium)

    A*/A = Choke Point/Nozzle Exit Area Ratio(Axial Position measured from choke point)

  • MFS CSO 90714

    “Estimator” ver. 1.0 for Spray Parameters

    Air Helium

  • MFS CSO 90714

    Understanding Particle Impact

    1 km Asteroid Impacting Ocean 300 Gigatons TNT Equivalent (10x Peak of All Cold War Nuke’s)

    Sandia Teraflops computer running CTH code100 million computational cells18 hr @ 91% capacity (8,192 of 9,000 processors)

  • MFS CSO 90714

    Computational Impact Model& Experimental Comparison

    Predicted peak temp.of 1280 K is below the

    melting point of Cu(1357 k)

    Cu

    Stainless Steel25 µm

    4

    3

    2

    1

    0

    - 1

    - 2

    - 3

    - 4

    Cu

    StainlessSteel

    t = 70 nst = 70 ns

    X (microns)- 4 - 2 0 2 4

    Y (

    mic

    ron

    s)

    Copper

    Steel

    Void

    Temperature K

    980

    900

    810

    720

    630

    540

    450

    380

    25 µm Cu Sphere into 304 Stainless at 600 m/s

  • MFS CSO 90714

    Summary

    • New materials / processing / manufacturing possibilities • Opportunity to be first to exploit market advantage• Several pre-competitive barriers need to be solved• Faster / cheaper / better to work together on pre-comp.• Partners will gain access to best technology & new IP