New Developments in Welding and Metal Additive Manufacturing Using Directed Energy Deposition (DED)

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Ian D. Harris, Ph.D.EWI, Columbus, OH USATechnology Leader, Arc Welding Founding Director, Additive Manufacturing Consortium, (AMC)iharris@ewi.org , 614.688.5131

Titanium Europe 2015 Conference, Birmingham, England, May 12, 2015

Advanced Manufacturing Technologies at EWI

Innovate, mature, commercialize Materials Joining and Manufacturing technology for industry

─ Laser processing─ Nondestructive evaluation─ Numerical modeling and simulation─ Plastic and composite fabrication─ Resistance welding─ Ultrasonic joining─ Weldability and mechanical testing;

metallurgical analysis

─ AcousTech™ Machining─ Additive Manufacturing─ Advanced arc welding─ Automation, sensors, controls─ Brazing and soldering─ Dissimilar materials joining─ Friction processing─ Hot forming

Outline

Existing and emerging metal AM processes and capabilities, focusing on arc welding DED

Associated priorities for manufacturing transition;─ Property data─ In-process monitoring─ NDE

New arc welding capability in Keyhole PAW and NG T-GMAW for Ti and other alloys

EWI capability, role, and interactions Summary

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EWI Activities in AM AM is a technology area at EWI. Expertise in lasers, materials, NDI, sensing and controls,

design, fusion welding (arc, laser, EB), modeling, and ultrasonics.

Focus Areas─ Metals─ Laser Powder Bed Fusion (EOS M280 DMLS)─ Material/Process/Property Development─ Complete Supply chain (materials, heat treatment, inspection)─ In process sensing.

Other AM Process Areas─ Arc-Based AM, Ultrasonic AM, Laser Directed Energy Deposition─ Repair AM

Operate the Additive Manufacturing Consortium Innovative Ceramics and Polymer AM at EWI-NY.

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The Additive Manufacturing Consortium

Mission: Accelerate and advance the manufacturing readiness of Metal AM technologies

Participation from Academia, Government, and Industry

Present timely case studies/research Execute group sponsored projects Collaborate on Government funding

opportunities Forum for discussion/shaping roadmaps

Goals:

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Current Members (2014) Rolls-Royce UT Aerospace Lockheed GE Aviation Woodward IHI Carpenter Powder

Products EOS LPW Technology, Inc B6Sigma NCDMM/America Makes NC State University of Louisville University of Toledo NIST LLNL NASA

Additive Manufacturing Supply Chain

Final PartMaterial

Properties

Path Planning

Finishing

Thermal History

Inspection

Qualification & Certification

AM Process Dimensional Control

Heat Treatment

CAD File

Material Process Control

Residual Stress

Process Sensing

Process Selection

Blue boxes are being addressed at EWI presently

Suite of AM Processes for Metals Laser and EB powder bed, from e.g. EOS, and Arcam in

confined envelope – 8-10-in cube, fine features (g/hr) –Primary AMC focus is PBF-L

EBW freeform fabrication - EB(FFF) (kg/hr) - Sciaky Laser powder and wire FFF from companies such as

POM, Optomec (LENS), EFESTO (kg/hr) VHP UAM – very high power ultrasonic AM of strip –

Fabrisonic (kg/hr) Emerging - Arc processes – SMD (GTAW CW), MER

(PAW), GTAW-HW (EWI IRD), GMAW-P, PTA (wire and powder) based on commercially available equipment for FFF (kg/hr)

Deposition Rate vs ResolutionCourtesy Boeing

Decreased Resolution

Incr

ease

d D

epos

ition

Rat

e

Large FFF parts‘Big metal’e.g. aero structure

Small intricate parts- e.g complex fuel nozzle – PBF-L and PBF-EB

GTAW-HWand otherarc processes

EBFFFVHP UAM

LAM

Advantages of AW for AM

High build rate e.g. 40 lbs/hr Freeform fabrication technique Ubiquitous supply chain for robotic arc welding Cell cost $150K+ with integrated AM software Properties for AW are readily available Large parts with integrated machining LM Aero calculate 60% cost reduction for Ti6-4

EBFFF versus forging for 16 ft long spar

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Capabilities: Robotic Arc Based AM AM is not limited to laser or electron beam equipment for FFF. Robotic arc based deposition methods:

─ Readily available equipment – transitioning to full robotic AM, CAD to part─ Still requires much of the process control infrastructure needed for laser and EB

AM processes. Deposition rates from 1 in3/hr to ~100’s in3/hr, up to 40 lbs/hr Serves aerospace and additional defense/commercial markets

Five beads on a 1.6 mm edgeGMAW-RWF

Defense ground vehicle 80 lb. build in Ti-6-4 using GTAW-HW

Nuclear componentUsing GMAW-P

GTAW (Hot Wire)

Wing stiffener/rib

Robotic GMAW-P and GTAW HW

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EWI has developed a full AM (CAD-to-part) capability based on a 6-9 axis robotic solution

Arc-Based Additive Manufacturing

Demonstrated arc-based processes for low cost, high deposition rate Titanium additive manufacturing─ GMAW-P─ RWF-GMAW─ PAW (Cold Wire)─ PTA (Powder)─ GTAW (Hot Wire) GMAW-P

PAW (Cold Wire)GTAW (Hot Wire) RWF-GMAW

PTA (Powder)

GTAW HW and PAW w/CW

Single bead ‘wall’GTAW HW PAW w/CW

Control Arm

AM with Arc Welding - Ti-6-4 Ground Vehicle Control arm with GTAW-HW First layer and completed deposit (bead by bead) on a 4’ by 4’

build plate (currently work on full AM software, for CAD to part) Markets including aerospace, nuclear, OGP, Heavy Mfg. for low

cost robotic AM

Fist layer, side 1 Side 1 complete

Ti Control Arm build with GTAW HW Completed Build on

Full-Size Control Arm Component – Side 2

Note – build not symmetric around build plate horizontal axis

Relative Flatness After Welding

End View of the Full-Size Control Arm Showing Relative Flatness of the Base Plate

GTAW-HW for AM at EWI

Recent work GTAW-HW for Ti-6-4 ELI (AWS WJ March 2014)

Full AM (CAD to part) robotic deployment – separate IRD

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GTAW-HW for FFF

ElementActual

Composition(wt%)

NominalComposition for Ti 6-4 ELI

Castings(1)

(wt%)

Maximum Permissible Composition for Ti 6-4

ELI Forgings(2)

(wt%)Hydrogen 0.0013 0.006 0.0125Nitrogen 0.0078 0.010 0.03Oxygen 0.077 0.11 0.13

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ID Specimen Orientation Condition

Tensile Strength

(ksi)

Yield Strength

(ksi)

Elongation(%)

Reduction in Area(%)

Baseline N/A Typical values for a

Ti 6-4 ELI castings(1) 120 110 13 22

1 Weld Direction As-welded 137.0 124.5 10.9 31.92 133.4 116.1 9.3 25.63 Weld Direction Solution heat

treatment + anneal115.2 105.8 14.5 26.5

4 116.8 106.1 13.7 28.65 Weld Direction Anneal 135.6 123.0 12.9 18.96 135.3 122.0 9.4 20.07 Build Direction As-welded 136.3 119.2 9.7 28.88 134.6 117.4 10.9 38.09 Build Direction Solution heat

treatment + anneal113.6 101.8 13.3 26.5

10 113.2 103.3 12.2 31.811 Build Direction Anneal 132.6 116.9 8.1 20.012 135.6 124.7 11.0 21.1

Table 1. Composition of Hydrogen, Nitrogen, and Oxygen in the Weld Deposit, Along with the Nominal Composition in Ti 6-4 ELI Castings, and the Maximum Permissible Composition in Ti 6-4 ELI Forgings (Met all requirements)

Table 2. Tensile Test Data for the Sub-Sized Specimens Along with TypicalTensile Test Properties of Bars Machined from Ti 6-4 ELI Castings (Initial work,close to requirements)

6-9 axis robotic AM with arc and laser welding and EBFFF

Hawk Gantry for large aerospace parts using arc and 20 kW laser capability (Ar/non-vacuum)

Sciaky EBFFF for F-35 JSF (vacuum) Very large parts

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Narrow-groove Tandem GMAW-P with Spin-Arc Deposition rate: 20 lbs/hr Travel speed: 15 ipm Calculated heat input: 46

kJ/in Single bead per layer Rotating arc gives good,

consistent sidewall fusion Combines benefits of both

narrow groove joint volume and tandem GMAW deposition rate to significantly increase productivity

TopTIG – Air Liquide

Torch with compact envelope and fixed high angle wire feed for work on ‘hybrid arc’ mechanized and robotic GTAW and Keyhole PAW/GTAW

Summary – Welding

High joint completion rate with low distortion on SECB or NG joints – suitable for nuclear, aerospace and other high quality fabrication

Keyhole PAW to ¾- and 1-in thick with SECB joint and no gap

Hybrid arc welding Hybrid keyhole PAW/GMAW-P, Keyhole PAW/GTAW

NG arc welding NG Tandem GMAW – thickness to 6-in with assured sidewall fusion.

Patented process, pursuing torch commercialization

Summary – Arc Welding DED

A wide range of arc welding tools available to increase productivity at required quality

Additive Manufacturing using arc welding─ Additive manufacturing processes with high deposition rate and

low cost ─ Aiming at larger parts expecting cost case to include full

machining of build─ Cost case better for long lead items such as forgings, and high

value base materials, in Ti and Ni-base alloys Need COTS integrated solutions with embedded

software (CAD to part) – already a few custom systems (MER, Norsk Titanium)

EWI has developed a full AM (CAD-to-part) capability based on a 6-9 axis robotic solution

Summary – Metal AM/EWI’s Role Holistic view

─ Many AM processes for metals, each with different merits─ Recognize that AM is an entire manufacturing chain which requires

engineering support for technology transition and implementation─ Much work to be done for manufacturing implementation, especially for

property data, in-process monitoring, and NDE Evangelists (Education)

─ E.g. Run and organize MS&T AM Symposia (usually 40-50 papers) each year – 130 submitted for Columbus event in Oct 2015

Trusted Agent─ Impartial, objective, equipment agnostic

Innovation─ E.g. sensor bed development/testing for in-process monitoring

Industry support─ Support clients in AM just as we support clients in materials joining─ Operate the AMC

Questions

Ian D. Harris, Ph.D.Technology Leader, Arc Welding Founding Director, Additive Manufacturing Consortium (AMC)iharris@ewi.org , 614.688.5131

http://ewi.org/technologies/additive-manufacturing/

EWI is the leading engineering and technology organization in North America dedicated to advanced materials joining and allied manufacturing technologies. Since 1984, EWI has provided applied research, manufacturing support, and strategic services to leaders in the aerospace, automotive, consumer products, electronics, medical, energy & chemical, government, and heavy manufacturing industries. By matching our expertise in materials joining, forming, and testing to the needs of forward-thinking manufacturers, we are successful in creating effective solutions in product design and production.