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WIRE VS. POWDER IN LMD

LAM 2018, 29. March 2018, Schaumburg

M. Sc. Jana Kelbassa, Dr. Andres Gasser, Dr. Norbert Pirch

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Fields of Application Laser Metal Deposition

INTRODUCTION AND STATE OF THE ART

RepairCoating AM

Surface coating & protection

Oil and gas

Chemical industry

…

Repair

Aerospace

Power generation

Tools & molds

…

Development of LMD processes

Tools & molds

Power generation

Aerospace

…

Current focus of work Development

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Technology description

Powder LMD

Process principle Typical processProcess characteristics

High diversity of additive materials

Applicable on sensitive surfaces

No undercut

Layers of 0,05 mm thickness up to several cm (multilayer)

Local application with low heat input and low modified base material properties

Automatable

Welding in constricted conditions

Layer based additive manufacturing also on 3D-surfaces

Coaxial powder feeding LMD

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Technology description

Wire LMD

Process principle Typical processProcess characteristics

Nearly 100 % material efficiency

No contamination of machine

Low costs for additive material

Good homogeneity of the material

Low safety and health issues

Local application with low heat input and low modified base material properties

Automatable

Layer based additive manufacturing also on 3D-surfaces

Easy combination with milling machine into hybrid machine

Coaxial wire feeding LMD

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MAIN TOPICS IN WIRE VS. POWDER IN LMD

Additve Material properties

− Powder

− Wire

System technology

− Powder feeding

− Wire feeding

Simulation

− Powder LMD process

− Wire LMD process

Results

Source: Fraunhofer IPT

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MATERIALS FOR POWDER LMD

Nickel base alloys− IN625, IN718, IN738, Hastelloy X, Waspaloy, Inconel

713, CM-247LC, Nimonic 263, Hastelloy C-276, Inconel 939, Haynes 230, MarM247

Titanium alloys− Ti-6-2-4-2, Ti-6-2-4-6, Ti-6-4, CP Ti

Aluminum base alloys− 4047, 6061, 7050, 7075, AlSi7Mg, AlSi10Mg, AlSi12,

Iron base alloys− 17-4PH, H13, 304L, 316L, 420SS, PH 138 Mo, 15-

5PH, AISI 4140 Cobalt-based:

− Stellite21, CM-64, Co6, CoCr Other-based:

− Cu-Ni (copper-based), A286 (iron-nickel-chromium alloy)

Powder materials (exemplary)

Atomization of nearly every metallic material is possible

Possibilities of material combinations

Source: LAM2012 Presentation 15

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INFLUENCE OF POWDER QUALITY ON LMD PROCESS RESULTS

2000 µm25X

25X

Supplier A

Supplier B

LMD carried out with– Identical process parameters– Identical process setup

Powder was obtained from two suppliers and specified with respect to:– Atomization technique (thermal inert-gas

atomization)– Chemical composition and residual

atmosphere– Nominal grainsize and morphology

LMD process with 13%Cr-Steel Powder

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MATERIALS FOR WIRE LMD

Alloy mixing in welding process

Wire stiffness high Reliable wire feeding Limited welding surface

quality (matt, oxidized, fine layer of particles)

Alloy present Wire stiffness low Challenging wire feeding Good welding surface quality

(glossy, no oxidation) High cost compared to filler

wire

Work hardened Manganese Alloys− T Fe10*, T Fe9*, etc.

Heat-treatable Tool steels− 1.2343, T Fe3*, T ZFe8*, etc.

Stainless ferritic und martensitic steels− 1.4820, T Fe7*, T Fe12*, etc.

Nickel base alloys− Inconel 718, T Ni2*, etc.

Abrasion-resistant steels− T Fe16*, T Fe20*, etc.

Copper Aluminum Alloys− T Cu1*, etc.

Cobalt base alloys− Stelloys, T Co1*, T Co2*, etc.

Titanium alloys− Ti6Al4V, etc.

Source: Fraunhofer IPT * Material designation Welding Alloy Group DIN EN 14700, T=filler wire, S=solid wire, WA=Welding Alloys

Wire materials (exemplary)

Generally there is a welding material for each material class.Unfortunately manufacturer specific configurations and names are common.

Comparison of solid wire and filler wire

Solid wireQuada QuInc 718

(Ø 1,2 mm)

Filler wireWA Stelloy 718-G

(Ø 1,2 mm)

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POWDER FEEDING SYSTEMS

Source: GTV Verschleißschutz GmbH

Disk powder feeder

powder feeding rate from0.5 to 300 g / min

Source: Medicoat AG

Powder feeder with oscillating conveyor

powder feeding rates from0.1 g/min to approx. 300 g/min

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POWDER FEEDING NOZZLES

5 mm 5 mm

off-axis coaxial-continuous coaxial-discrete

good accessibilitydirection dependent

small powder focus (less than 100 mm possible)

robust and suited for 3D-cladding

5 mm 5 mm 5 mm

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Characterizing the powder gas jet – setup

POWDER NOZZLE QUALIFICATION BY POWDER JET MEASUREMENT

Sensor module

Control module

PLCexhaustion

cameraoptics

axis

• PC

• Control

• Power supply

• safety

• …Illumination-laser

Illumination module

illumination

level 0

level 1

level 2

level 3

level 4

level 5

level 6

level 7

Laser line moved to each measurment level

level 8 …

Nozzle Tip

Laser Line enlightens a 200µm slice of the powder jet captured by a Camera

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Basic design variants for wire-based LMD

Feed direction

Wire feeding

Focusing optic

Laser beam

Inert gas

substrate

αD

x

yz

Feed direction

Wire feeding

Coaxial head

Laser beam

Inert gas

substrate

αL

αSG

x

yz

W-LMD with lateral wire feeding W-LMD with coaxial wire feeding

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PROCESSING HEADS FOR COAXIAL WIRE LMD

ring-shapedintensity

generation

focus

wire feed 1

3

4

5

2

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POWDER LMD MODELLING PHYSICAL PROCESSES

1) Beam propagation: I=I(x, y, z) 2) Particle density: n=n(x, y, z) 3) Interaction of laser beam with powder particles

Transmitted Intensity Itrans (x, y, z)

Temperature of particles

4) Equations: Transient heat flow Pressure balance Mass balance

5) Results Track geometry Temperature distribution Local solidification conditions Powder efficiency

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Tactile 3D-measurement

Measurement ofrectangularity, flatness

Referring to DIN EN ISO 1101

Form tolerances

Specimens built up in lying position

HT: referring to AMS 5662

Static load tests refering toDIN 50125

Mechanical propertiesSurface properites

Optical 3D-measurement

Measurement of surface rougness

Referring to DIN EN 4287,DIN EN 11562

5 mm20 mm 5 mm

PROCESS COMPARISONDirect comparison of LMD and SLM concerning following aspects:

ICTM AachenInternational Center forTurbomachinery Manufacturing

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COMPARISON OF POWDER AND WIRE LMD

Laser cladding processes

Metal deposition on 3D surface (layer-by-layer) Deposition on free-form parts Local application with correlating local heat input

and material property modification Potential for functional integration:

Light weight construction, heat- and mass transfer, subsequent individualization, sensor integration, etc.

Overhang and undercuts are possible but limited Support structures not necessary Direction independent material feed possible Theoretically unlimited building space with robotic

aided systems Combination with milling machines to hybrid

machines

Powder LMD

Material gradients possible Powder handling required

(contamination, respirable) No risk of collision powder

materials Limited material efficiency

Wire LMD

Material loss and contamination of the machine are low

Feedstock is free of defects Material efficiency 100 % Lower material costs Wire feeder prone to errors

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PROCESS OVERVIEW ULTRA-HIGH-SPEED LASER MATERIAL DEPOSITION

State of the art: EHLA for rotationally symmetric components (lathe functionality)

Coating to improve wear and corrosion resistance of e.g. shafts, disks, cylinders

Layer thickness 25 ... 500 µm

Small heat-affected zone, various material combinations possible

Conventional LMD EHLA

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Topics

Save the Date Speakers at Conference 2017

Industrie 4.0 with Regard to Manufacturing Turbomachinery Parts

Innovative Process Monitoring Systems

Advanced Machining

Innovative and Newly Developed Materials

Additive Manufacturing

Laser Based Repairs

Live Presentations

Outlook

ICTM ConferenceFebruary 6th-7th, 2019

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Thank you very muchfor your attention!

ICTM AachenInternational Center forTurbomachinery Manufacturing

Contact:

M. Sc. Jana KelbassaTel: +49 241 8906-8331Fax: +49 241 8906-121jana.kelbassa@ilt.fraunhofer.de