Advances in Arc and Hybrid Welding, and AM of Titanium AlloysITA Conf 2010, Orlando

Ian D. Harris, Ph. D.Technology Leader, Arc WeldingTechnical Director, AMC

614 688 5131iharris@ewi.org

Outline

Welding Titanium- Novel arc welding- Laser and Hybrid Laser Arc Welding (HLAW)

Additive Manufacturing (AM)- Arc Welding

Additive Manufacturing Consortium (AMC)- Need for Collaboration

Roadmap - High Consequence Arc Welding

Heavy fabrication and military applicationsNuclear fabricationB&PVAero and Space applications Using micro-TIG at 0.5 lb/hr through orbital GTAW to out-of-position NG Tandem GMAW at 35 lbs and /hrHLAW for X80, and X100 linepipe, HSLA 100 steels for carrier and submarine hulls, low-alloy steels for B&PV applications, etc.Alloys of titanium, nickel, aluminum, copper, stainless steels (all grades from austenitic to superduplex)

Precision GMAWBenefits:

Reduced heat-input, residual stress, distortionPrecise deposit shape controlFiller metal coaxial with the torch- Less complex mechanism - Easier to automate

Cost savings (compared to dabber GTAW or laser)- Lower capital equipment cost- Higher productivity

Need:Assess feasibility for high-alloy build-ups

Precision GMAW

1.5 mm Ti6-41.5 mm Ti6-4

Nickel alloy clad on steel< 0.5% dilution achievable

Hybrid Arc Metal Transfer

Precision-GMAW Build-Up

1.5mm

Stainless steel edge build-up• 18 ipm Travel speed • Heat-input < 1 kJ/in

Low Power GMAW-P of Ti

Laser Stabilized Arc Welding

Yb – Fiber Laser Welding of Ti 6-4

Laser Welding of Thin Sheet Ti 6-4

Robotic Yb-Fiber Laser welded flat and formed sheet products in the thickness range of .032” -.125”Dual fillet welds with wire addedDistortion related to low welding speed and dual fillet weld rather than single pass ‘skid’ weld

Hybrid Laser Arc (HLAW)

Benefits of Hybrid Laser Arc

High Energy Density of Laser- Deep Penetration- High Travel Speed

Filler Wire Addition of GMAW- Gap Tolerance- Alloying Elements

Suitable for steels, stainless steels and nickel-based alloys

Enabling Tech - Yb-Fiber Laser

High efficiency; >25% (vs. 3 to 6%)Long potential diode life; > 25,000 hoursCompletely fiber generated and delivered

Very scalable; 20 kW systems exist (70 kW sold)Robust systemNear Perfect Beam

Prototype P450 Hybrid Head

Upgraded TPS3200 to TPS 5000 for 500 A GMAW capability with higher WFS and deposition rate for increased weld throatIncreased travel speed to 120 in/min (3 m/min) by gearing15-kW laser power currently availableEffective throat up ½-in (13-mm) single pass

Legend

• Friction Stir Welds • Hybrid Laser Welds• GMAW-P Welds

Ti 6-4 Demo Hull Fabrication

Lower Glacis to Front Glacis Corner Joints (LBW and HLAW)

Root pass (LBW only)- 20-IPM Travel speed- 4-kW Laser power

Cap pass (HLAW)- 15-IPM Travel speed- 215-IPM Wire feed speed

• 0.035-in wire- 2-kW Laser power

Tooling Model Tooling Assembly with welded part

Ti 6-4 corner joint with multi-step path geometry (0.5-in to 0.25 and 0.5-in)

Bulkhead to Front Glacis/Outer Sidewall/Sponson/Inner Sidewall (GMAW-P)Ti 6-4 fillet joint with multi-step path geometry (0.5-in to 0.25 and 0.5-in)Fillet weld parameters:- 20-IPM Travel speed- 400-IPM Wire feed speed

• 0.045-in wire

Tooling Model Final Assembly

AM – Progressive Layers

Build in layers, Stress relieve/PWHT, Machine

AM Processes for Metals

EBW freeform fabrication - EB(FFF)Laser powder and wire for FFFLAM, LENS, DMLS, from companies such as Arcam, EOS, POM – powder and wire based laser and EB metals AM in confined envelope Arc processes – GTAW-HW, GMAW-P, PTA (wire and powder) based on commercially available equipment for FFFVHP UAM – very high power ultrasonic AM

Example Metals AM Processes

Concept Laser DCM®

EOS DMLS®

MTT SLM®

Phenix Systems

Optomec LENS®

MTS Aeromet LAM(No longer in

business).

Sciaky EBFFF

Arcam EBM®

Deposition Rate vs Resolution

Courtesy Boeing

Decreased Resolution

Incr

ease

d D

epos

ition

Rat

e

Additive Manufacturing -Feature Size CapabilityFrom single beads stacked upon each other (bottom)To large features at high deposition rates (top)Mitigated by balance of net-shape, metallurgical requirements, mechanical properties (tensile, fatigue, etc)

Arc-Based Additive ManufacturingDemonstrated arc-based processes for 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)

Proprietary to Lockheed Martin Copyright 2009

Titanium Additive Manufacturing

Process Productivity Distortion

GMAW-P Medium Medium

RWF-GMAW Medium Low

PAW (Cold Wire) Low Medium

PTA (Powder) Very Low Low

GTAW (Hot Wire) High High

Arc-based processes are generally less capital intensive and more productive than many other additive manufacturing processes

Example Applications

EB FFF and DMLS parts for aerospace components

Example Applications

Land vehicles- OEM- Repair

Power generation and nuclear

AM Evaluation Stages

Evaluation Stages – AMS-4999 Revision- 1 Initial Screening- 2 Process/Source Approval- 3 Deposition Parameter Approval- 4 Approval on Non-Critical Flight Hardware- 5 Approval of Critical Flight Hardware

MMPDS data generationNon-flight Hardware Qualification stops at Stage 4

Collaboration Needed

Wide Range of Processes Necessitates InvestigatingEach Process in Detail – this is very expensive and requires

collaboration

Initial Acceptance Values Based on LAM Process FormLower Bound for Tensile Properties, Typical forFatigue Crack Initiation

Stage 2 Evaluation of Several Processes Necessary toFully Validate Use of LAM Values for All Approvals ofProposed AMS 4999 Revision

Stage 2 Evaluation of 6 to 7 Processes Needed forCertainty of Generating MMPDS Allowables

The Answer: AMC

The Additive Manufacturing Consortium (AMC) was founded to provide a U.S. AM forum and is already attracting international interestConsortium of industry, government, and research organizationsMission: Advance the manufacturing readiness of metal AM technologies to benefit consortium members

Time to deployment

Man

ufac

turin

g R

eadi

ness

University & Federal Labs

Manufacturers & Suppliers

Additive Manufacturing

Consortium

MRL 3-7Significant commercial impacts in 2-5 years

MRL 8-10Incremental improvements and implementationShort time horizon

MRL <3High-risk basic research and educationLong time horizon

Advancing Manufacturing Readiness

AMC StructureEncompass a wide spectrum of manufacturersInclude technology and material suppliersEngage a technology network of research partners; “National Test-Bed Center” Creates a non-competitive environment for industry to share experience and best-practicesLeverages public and private funding sourcesDistinct from university-led centers which often focus on education and basic-research

Conclusions

Continued development of arc and hybrid processes for welding titanium alloys for commercial and military applicationsHLAW offers potential for 5/8-in (15 mm) single pass with a SECB joint or 5/8-in root face using a 15kW laserAMC offers collaboration for development of metals AM using Laser, EB, arc and other processes

Questions?

Ian D. Harris, Ph. D.Technology Leader, Arc Welding

614 688 5131iharris@ewi.org