ARLPenn State

Penn State Applied Research Lab

Laser Additive Manufacturing Technology

Presented at:Direct Digital Manufacturing of Metallic Components Workshop

Prepared by:Rich MartukanitzEric WhitneyShawn KellyTom Donnellan

May 11, 2010

ARLPenn State ARL/PSU BackgroundARL/PSU BackgroundARL/PSU Background

As a University-Affiliated Research Center (UARC) ARL Penn State…“…maintains a special long-term strategic relationship with DoD for technology development and engineering applications.”

Established in 1945 by the NavyLargest Interdisciplinary Research Unit at Penn State – 1,200+ faculty/engineers, staff, students and 350,000 sq.ft. Classified facilities and programs to SCIResearch expenditures FY 2009: $165MDesignated a University Affiliated Research Center by DoD in 1996

ARLPenn State

MISSIONTo be the preeminent source of innovative technologies-materials, process, manufacturing, design and logistics technologies for affordable, high performance DoD platform structures and systems.

Materials ProcessingMaterial Design and CharacterizationProcess DevelopmentAdvanced Coatings

Advanced CompositesMarine, Land, and Aerospace Systems

– Design and Analysis– Materials Char./Qual.– Process Optimization– NDE, Repair

Laser ProcessingLaser PhysicsProcess TechnologySystem Integration

Manufacturing SystemsAutomated Conceptual Design/Trade Space ExplorationSimulation and Modeling for ManufacturingShearography, Spectrometry, Inspection, NDTEnvironmental Technology

MAJOR PROGRAMSiMAST, Drivetrain Technology Center,DTRA University Partnership, Laser Processing Consortium

Materials and ManufacturingMaterials and Manufacturing

Mission and OrganizationMission and Organization

Systems Operations & AutomationCondition Based MaintenanceSense and Respond LogisticsIntegrated Health Management

ARLPenn State

Tech

nolo

gy D

evel

opm

ent

Tran

sitio

n to

Indu

stry

Improved Process Process Sensing Material Response Process Development:Understanding and Control Models New Hybrid Processes

Application of Laser Deposition for Laser Repair of Portable Laser RepairLASCOR Commercial Applications Undersea Components for VLS Components

(U.S.S Mt. Whitney) (NUWC - Keyport) (Pearl Harbor NSY)

l sv

l sv

l sv

l sv

1990 2000 2010

Work-pieceElectric Arc

Gas Metal ArcWelding Torch

Keyhole

Molten Pool

Focused LaserBeam

Inert ShieldingGas

Pudd

le W

idth

Time [sec]0 5 10 15 20 25 30 35 40 45 500.25

0.3

0.35

0.4ActualTrend

Materials and ManufacturingMaterials and ManufacturingLaser Processing

Technology Development & ImplementationLaser ProcessingLaser Processing

Technology Development & ImplementationTechnology Development & Implementation

ARLPenn State ARL Laser Additive Manufacturing

OutlineARL Laser Additive ManufacturingARL Laser Additive Manufacturing

OutlineOutline

Flexible Fabrication of Titanium (Acquisition Cost and Schedule)

Acoustically Tailored Structures (Tailorability)

- Modeling and Simulation

AV-8B Compressor Blade Repair (TOC)

Discussion Topics/Technology Needs

ARLPenn State

Flexible Fabrication of Titanium Background

Flexible Fabrication of Titanium Flexible Fabrication of Titanium BackgroundBackground

Work on Metal Deposition Processes – 1980s

– Brown, C.O., E.M. Breinan, and B.H. Kear, Method for fabricating articles by sequential layer deposition, U.S. Patent 4,323,756, United Technologies Corporation, April 6, 1982

– Arcella, F.G. and G.G. Lessmann, Casting shapes, U.S. Patent 4,818,562, Westinghouse Electric Corporation, April 4, 1989

– Pratt, V., W.D. Scheidt, and E. Whitney, Fabrication of Shapes by Layered Deposition, U.S. Patent 5,038,014, General Electric Company, August 6, 1991

Work on Rapid Prototyping Technologies – 1980 & 1990s– Stereo lithography

DARPA/ONR Interest in Cost Reduction of Ti Components– Flexible Fabrication of Titanium Program

• Dr. R. Crowe (DARPA) and Dr. G. Yoder (ONR)• APL/JHU, ARL/PSU, MTS

ARLPenn State

Development System

Argon Gas

Titanium Powder Fluidized Bed in the Atmosphere Control Chamber

Oxygen Sensor

CNC Translating Cover

Powder FeederOxygen Sensor

Fluidizing Gas

Atmosphere ControlChamber

Target Chamber

Argon Gas

High Power CO Laser2

Y

X

}VisionSystem First DARPA Free

Forming System

Flexible Fabrication of TitaniumFlexible Fabrication of TitaniumFlexible Fabrication of Titanium

ARLPenn State

Powder feeding was perfected for titanium alloys in argon atmosphere –Made billets and rudimentary shapes–Characterized material via chemical and mechanical testing–Performed economic analysis

Flexible Fabrication of TitaniumFlexible Fabrication of TitaniumFlexible Fabrication of Titanium

ARLPenn State

Approximately 12 inches

Flexible Fabrication of TitaniumFlexible Fabrication of TitaniumFlexible Fabrication of Titanium

ARLPenn State

Ingot 032296: Pre-Alloyed Ti-6Al-4V, L2

200 μm

Ti-6Al-4V Typical Thin Section Casting

200 μm

Ti-6Al-4V Typical Thick Section Casting

200 μm

Ingot 022396: Blended Ti-6Al-4V, L2

200 μm

Flexible Fabrication of Titanium Ti-6-4 Microstructures

Flexible Fabrication of Titanium Flexible Fabrication of Titanium TiTi--66--4 Microstructures4 Microstructures

ARLPenn State

Element Powder, wt. % Laser Formed*, wt. %V 3.97 3.80 Al 6.20 5.91 Fe 0.232 0.199 O 0.230 0.237 N 0.032 0.037 H 0.012 0.004

* Vacuum Mill Anneal, 1450°F (788°C) 2 hrs., argon quench

Interstitial contamination low, manageable

Flexible Fabrication of Titanium Chemical Analysis, Pre-alloyed

Flexible Fabrication of Titanium Flexible Fabrication of Titanium Chemical Analysis, PreChemical Analysis, Pre--alloyedalloyed

ARLPenn State

SEM Microprobe AnalysisTi-6Al-4V Ingot 032296 : Pre-alloyed Powder

1.0

10.0

100.0

0.00 0.20 0.40 0.60 0.80Z - Position (inches)

wei

ght % Ti

AlV

SEM Microprobe AnalysisTi-6Al-4V Ingot 022396 : Blended Powder

1.0

10.0

100.0

0.00 0.20 0.40 0.60 0.80Z- Position (inches)

wei

ght % Ti

AlV

Starter TargetInterface Region

In situ alloy fabrication possible

Flexible Fabrication of Titanium Ti-6-4 Microprobe Analysis

Flexible Fabrication of Titanium Flexible Fabrication of Titanium TiTi--66--4 Microprobe Analysis4 Microprobe Analysis

ARLPenn State

Flexible Fabrication of Titanium Mechanical Properties

Flexible Fabrication of Titanium Flexible Fabrication of Titanium Mechanical PropertiesMechanical Properties

Laser Formed Fatigue Test Results

ARLPenn State

Method #2

Plate volume (in3) 1,728

Ribs additive deposit (in3) 396 Ribs additive deposit (pounds) 63.8

Cross-ribs additive deposit (in3) 45 Cross-ribs additive deposit (pounds) 7.3

Total additive deposit (pound) 71.0 Powder usage (pounds) 88.8

Plate (pounds) 278.2 Total (pounds) 349.2

Deposit time (hours) 22.2 Total job time (hours) 25.2

Cost EstimatesLaser operator 630$

Assistant laser operator 394$ Thin plate 7,025$

Powder 2,664$ Argon 1,060$

Helium 13$ Process electricity 266$ Cooling electricity 117$

Metal waste disposal 18$ Heat treatment 349$

Laser maintenance 427$ Other equipment maintenance 222$

Floor space 123$ Depreciation expense 2,304$

SUBTOTAL $ 15,612

Time per unit (hours) 25.2 Cost per unit 15,612$

Units per year 121.9 Total cost per year 1,903,162$

Acceptable units per year 109.7 Total acceptances (pounds) 38,317

Cost per pound accepted $50

Method #1:

Beginning Volume, in3 8,640 Beginning Mass, lbm 1,391.0

Rough MachiningPlate Volume, in3 1,728.0 Rib Volume, in3 396.0 Cross-rib Volume, in3 45.3 Rough Volume, in3 2,169.3 Rough Ending Mass, lbm 349.2 Mass removed by machining, lbm 1,041.8 Machining time, hours 115.8 Total time, hours 118.8

Cost EstimatesThick plate 32,342$ Rough machining 9,500$

Time per unit (hours) 118.8 Cost per unit 41,842$ Units per year 32.3Total cost per year 1,352,988$ Acceptable units per year 29.1Total acceptances (pounds) 10,164 Cost per pound accepted $133

Conventional - $133/lbs.

Laser Deposition - $50/lbs.

Buy-to-fly

Flexible Fabrication of TitaniumTi-6-4 Component Cost Comparison

Flexible Fabrication of TitaniumFlexible Fabrication of TitaniumTiTi--66--4 Component Cost Comparison4 Component Cost Comparison

ARLPenn State

Monolithic alloys– Ti-6Al-4V

• Powder• Elemental powder

blends– Nickel-aluminum-

bronze (NAB)– γ-TiAl (Ti-47-2-2)– 17-4PH stainless

steel– Alloy 625– Alloy 690

Composite/Graded– NAB graded to Alloy

625, 17-4PH SS, W– 308SS/Stellite 6

layered– CP Ti + W particle

composite

Materials Processed via Laser Additive Manufacturing at ARL

Materials Processed via Laser Additive Materials Processed via Laser Additive Manufacturing at ARLManufacturing at ARL

ARLPenn State

Submarine propellers are NAB engineered structures which are long lead items for platform

Base processes: casting and secondary processes

Laser additive manufacturing : cost and schedule benefits for submarine propeller applications

Laser Additive Manufacturing Fabrication of Turbomachinery

Laser Additive Manufacturing Laser Additive Manufacturing Fabrication of TurbomachineryFabrication of Turbomachinery

ARLPenn State

Condition Test Direction UTS (MPa) YS (MPa) % elong (2 in.) % R of AN2 Y 665 265 25.0 23.8N2 Y 645 261 21.0 22.4N2 Y 665 256 26.0 26.0N2 Y 648 242 26.0 27.2Ar Y 679 271 27 27.2Ar Y 689 296 23 23.8Ar Z 662 268 30.0 27.9Ar Z 662 270 26.0 28.6Ar Z 662 268 27.0 28.6Ar Z 655 265 29.0 28.6

ASTM B148 - 585 (min) 240 (min) 15 (min) -

z

y

xSpecimen locations, 3 shown, but

may be adjusted

152 mm

89 mm

38 mm

NAB Process & PropertiesNAB Process & PropertiesNAB Process & Properties

ARLPenn State

Free-Forming process has potential to– Produce parts with material properties superior to cast parts

for less cost/schedule (reduce critical path by 1 year)– Make a variable property blade for structural acoustic tailoring– Make a thick NAB “skin” with internal void for treatment

Integral pocket free-formed

Laser Additive Manufacturing of BladesLaser Additive Manufacturing of BladesLaser Additive Manufacturing of Blades

ARLPenn State

Structural-acoustic design is important in determining the sound radiation from underwater vehicles

Inflow Turbulence Interacting with Blade Leading Edge

Boundary Layer Turbulence Interacting with Blade Trailing Edge

Low Frequency

Mid Frequency

High Frequency

HullVibration/ Radiation

BladeVibration/ Radiation

Overall Noise Signature

Typical Radiated Noise Signature Typical Radiated Noise Signature Typical Radiated Noise Signature

ARLPenn State

Single blade spanwise material property variations:

E →

10 to 50 Msiρ →

0.12 to 0.37 lb/in3

12

34

56

78

910

1112

1314

1516

1718

1920

2122

2324

2526

2728

2930

3132

3334

3536

3738

3940

4142

4344

4546

4748

4950

5152

5354

5556

5758

5960

6162

6364

-32

-30

-28

-26

-24

-22

-20

-18

-16

Sum

of t

he F

irst F

ive

Rad

iatio

n Ef

ficie

ncie

s

“Optimum” case

NAB

Predicted radiation efficiency reductions of first five modes up to 10 dB relative to NAB

Structural Acoustics Analytical ResultsStructural Acoustics Analytical ResultsStructural Acoustics Analytical Results

ARLPenn State

How can these optimized designs be fabricated?

Aluminum

Bronze Alloy

40/60 Mix of Tungsten and Bronze Alloy

20/80 Mix of Tungsten and Bronze Alloy

Design 1 – 2.2 dB Reduction Design 2 – 1.3 dB Reduction

Addresses trailing edge forcing function

Reduces radiation efficiency – Less sound for the same

vibration

Solution: Laser Additive Manufacturing

Fabrication of Optimized DesignsFabrication of Optimized DesignsFabrication of Optimized Designs

ARLPenn State

NAB+W 

Segregation

NAB

Layer 

Interface

NAB

17‐4 PH 

Tip

Internal 

Feature

Delaminati

on

Issues with LAM of Graded StructuresIssues with LAM of Graded Structures

Need for better understanding of processNeed for better control of process

Process ResultsProcess ResultsProcess Results

ARLPenn State

Heat and Mass Transfer

Transport Models

A.C. Naber, Penn State University, 2005.

Beam - Material Interaction Microstructure Models

R.W. McVey, Penn State University, 2007.

R. W. McVey,  et. al.,  J. Laser Appl., 19(4), pp.214, 2007

Conduction

S.M. Kelly, Virginia Tech, 2004

MorphologyS.S. Babu and R.P. Martukanitz, 2006

Thermodynamic

M. Keller and S.M. Kelly,  ICALEO 2006

Development and Validation of LAM Process Models

Development and Validation of LAM Development and Validation of LAM Process ModelsProcess Models

ARLPenn State

Decreasing Heat Input

Basketweave-α

“Colony-α”

Understanding Microstructure Evolution During LAM of Ti-6Al-4V

Understanding Microstructure Evolution Understanding Microstructure Evolution During LAM of TiDuring LAM of Ti--6Al6Al--4V4V

ARLPenn State

2009 DURIP Award - Installed December 2009

OPTOMEC Laser Engineered Net Shaping (LENS™) System

Features:– Dual powder feeders.– Material grading capability– Single and multi-mode fiber capable – Closed-loop melt-pool control.– Inert processing chamber.– Specifically designed deposition

heads.

Addresses many of the shortfalls of previous ARL tool.

IPG Photonics 500W Single Mode Yb Fiber Laser

OPTOMEC LENS MR-7

New LAM CapabilityNew LAM CapabilityNew LAM Capability

ARLPenn State

F402 engine compressor blade tips in the AV-8B become worn, resulting in a performance decrease, requiring replacementFRC-East estimates that Rolls-Royce will not be able to meet their demand for new (replacement) compressor blades, potentially impacting force application. Costs associated with replacing worn blades is $929K/yearFRC does not have reliable NDT capability to detect porosity at the required levels.

http://en.wikipedia.org/wiki/Rolls-Royce_F402-RR-408

LAM-Based Repair of Compressor Blades in the AV-8B Harrier

LAMLAM--Based Repair of Compressor Based Repair of Compressor Blades in the AVBlades in the AV--8B Harrier8B Harrier

ARLPenn State

Key Technology Solutions:– Key Technologies:

• Laser Additive Manufacturingo H&R Technology, Huffman Corp., Optemec Inc.

• High Resolution Ultrasonic Inspection– Gaps and Barriers:

• Repairo Standardized evaluation of repair properties.o Development of systems for repair of compressor

blades.o Qualification testing.

• Inspectiono Ability to detect 0.005 in. defect at 90 % POD at

95% confidence interval.

www.usmc.mil #200491171130

Repair of Compressor Blades in the AV-8B Harrier

Repair of Compressor Blades in the Repair of Compressor Blades in the AVAV--8B Harrier8B Harrier

ARLPenn State

Repair Vendor B- Powder

Repair Vendor A- Ribbon

Repair Vendor C- Powder

Proof of Concept Repairs on Stage 3 Compressor BladesProof of Concept Repairs on Stage 3 Compressor Blades

Process DevelopmentProcess DevelopmentProcess Development

ARLPenn State

Metallurgical Coupon Dimensions

Vendor A

Vendor B

Vendor C

Metallurgical CouponsMetallurgical CouponsMetallurgical Coupons

ARLPenn State

Vendor A

Vendor B Vendor C

Base Metal

Microstructures appear to be indicative on non-equilibrium

phases as a result of rapid cooling

Microstructures appear to be indicative on non-equilibrium

phases as a result of rapid cooling

Metallographic Inspection Metallographic Inspection Metallographic Inspection

ARLPenn State

Project: A2177 F402 Compressor Blade Repair and Inspection

Objective: Demonstrate that repaired properties do not pose a flight risk through the execution of an approved, evaluation and pilot-qualification test plan.

Parameter Baseline Value Requirement Threshold Value

Requirement Objective

Value

How to Measure (quantity per repair

process)

Date to be Achieved

Achievement History

How Demonstrated

Repair Chemistry

AMS 4999 Specification meet meet

Bulk and Interstitial Element Composition of Repair Metallurgical

Coupon (2)

1 mo ARSMAR 10

75% of Samples Rec’d -

Repair Metallurgy

AMS 4999 Specification

Transformed α+ β

microstructure in fusion zone; no alpha case; no

cracking.

meet Repair Metallurgical Coupon (2)

1 mo ARSMAR 10

75% of Samples Rec’d -

Tensile-X

AMS 4911σY ≥

120 ksiσUTS ≥

130 ksiεF ≥

10%

meet exceed Repair Test Coupon(3)

3 mo ARSMAY10

75% Samples Rec’d -

Tensile-Z

AMS 4911σY ≥

120 ksiσUTS ≥

130 ksiεF ≥

10%

meet exceed Repair Test Coupon(3)

3 mo ARSMAY 10

75% of Samples Rec’d -

Flexural Fatigue

Fatigue Life Curve of

Unrepaired Test Coupon

meet exceed

Fatigue Life Curve (105

to 107 cycles)Repair Test Coupon

(9)

6 mo ARSAUG 10

75% of Samples Rec’d -

Component Frequency Analysis

New Unrepaired HPC Blade

No effect of repair on frequency response NA Repaired HPC Blade

(TBD) MAY 11 - -

Continued next slide….

Metrics - RepairMetrics Metrics -- RepairRepair

ARLPenn State

Laser Additive Manufacturing has potential for cost and schedulebenefit for Navy, DoD, and commercial applications

– Performance/cost trade based selection of candidate components

– Repair/replacement benefits for maintenance community

Laser Additive Manufacturing has unique benefit in tailored structures

– design of a multi-alloy components which can be made for about the same cost as a monolithic structure

ConclusionConclusionConclusion

ARLPenn State

Starting Material – quality, cost, availability

Application Guidelines– multifunctional structure design development

Equipment Design Features– scalability– process control

Certification Protocol Development

Discussion Topics/Technology NeedsDiscussion Topics/Technology NeedsDiscussion Topics/Technology Needs