Additive Manufacturing at Lockheed Martin

Hank PhelpsSr Staff M&P EngineerLockheed Martin Aeronautics

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© 2019 Lockheed Martin Corporation. All Rights Reserved. Approved for Public Release AER201709030 & AER201801020

Introduction

• Overview of Lockheed Martin• Business Unit Structure

• AM Capabilities Across LM

• LM AM Deployments

• Highlights of AM Development Done for Fighter Application

• Summary

Lockheed Martin at a Glance

Lockheed Martin Business Areas

LM Additive Manufacturing Capabilities

• Small Polymer• Fused deposition modeling for thermoplastics • Stereolithography • Other technologies

• Large Polymer• 2-robot cluster for carbon-reinforced ABS • Big Area Additive Manufacturing (BAAM) system for thermoplastics

• Small/Medium Metal• Electron beam powder bed for titanium • Laser powder bed for aluminum, titanium, & steel

• Large Metal• Electron beam wire-fed for all Titanium/Inconel• Wire-Arc Additive Manufacturing (WAAM) for steel and aluminum

• Advanced Materials• Aerosol jet for nanomaterial applications

LM Deployed Additive Manufactured HW

F-16 Drag Chute Frame

Background

• The F-16 Drag Chute Frame• Aft End of Canister that holds the Drag Chute for Short Field Landings

• Currently an A357 Casting• Issues with getting timely delivery

• Quality issues impacting fit-up and assembly

• Canister supplier requested a re-design to eliminate casting

• Evaluated Laser-Powder Bed Fusion (L-PBF) Alternative• Fabricated 6 Proof-of-Concept Parts at 3 Different Vendors

• Generated Preliminary Property Data

Proof-of-Concept Builds

Machines Used E0S M280, SLM 280 and Concept Laser X1000

Thermal Treatment Selection

A357-T61 Spec Min Values w/o Casting Factor Ult=50 ksi Yld=40 ksi

• Difficulty Meeting Properties with Typical HT

• Lower Temperature SR Had Competitive Properties

Mechanical Property Evaluation

Chemistry

AX4-CHM-XZ-1 AX6-CHM-XZ-1 Min % Max %

Si 10.23 10.45 10.48 9.00 11.00

Fe 0.18 0.19 0.21 0.55

Cu 0.01 0.01 < 0.01 < 0.05

Mn 0.01 0.01 0.01 0.10

Mg 0.35 0.28 0.31 0.25 0.45

Ni 0.01 0.01 0.01 0.05

Zn 0.01 < 0.01 < 0.01 < 0.10

Ti 0.01 0.01 0.01 0.15

Pb .01 < 0.01 < 0.01 < 0.02

OT 0.15 < 0.10 < 0.10 < 0.15

OE 0.05 < 0.05 < 0.05 < 0.05

Al Balance Balance Balance

Powder CertDeposited Samples LMA-PA002 Req

Balance

Element

Density & Porosity

Microstructure

Looking Down on XY Plane

Perpendicular to Z Axis

Tensile Properties

Typical Stress vs Strain Curves

Compression Yield Strength

Bearing StrengthE/D = 2.0

Izod Impact Strength

JIC Results

Specimen Orientation JIC

AX8-J1C-XZ-1 XZ 26.4

AX8-J1C-XZ-2 23.2

AY4-J1C-YZ-1 YZ 27.4

AY4-J1C-YZ-2 24.6

AX8-J1C-ZX-1 ZX 15.9

AX8-J1C-ZX-2 21.1

SN Fatigue

AlSi10Mg

A357-T61

Static Data

Compression

Data

IZOD Impact

DataJIC

ASTM E111 ASTM E9 ASTM E23 ASTM E1820

TUS (ksi) TYS (ksi) e (%) RA (%) Mod (Msi) CYS (ksi)BUS

(ksi)

BYS

(ksi)

Impact Str

(ft-lbs)

Toughness

(ksi-RtIn)

X 56.1 34.9 8.8 11.4 10.8 31.1 98.4 81.3 XZ = 22.7 XZ = 24.8

Y 55.8 35.2 8.6 10.8 10.9 31.0 100.3 86.3 YZ = 23.7 YZ = 26.0

Z 60.7 31.6 5.3 8.1 10.4 36.6 99.2 84.1 ZX = 14.7 ZX = 18.5

ASTM E8 ASTM E 238

Orientation

Tensile DataBearing Data

(e/D=2.0)

Observations

• Tensile ultimate highest in Z but yield, e & RA lowest in that direction compared to X or Y

• Compression yield strength was highest in the Z direction while the X & Y results were comparable

• Bearing ultimate strength was relatively insensitive to specimen orientation

• Impact strength was comparable when impacting across the X or Y directions while across the Z direction had lowest impact strength (36% lower than X & Y)

• Fatigue results comparable for all orientations tested

Comparison of AM vs Casting Values

Conclusion

• AM AlSi10Mg is a Viable Alternative for Aluminum Castings• Not a drop-in replacement

• Some properties lower than castings• Fty, Fcy and Bearing

• Best Near Term Uses• Non-critical applications

• Complex geometries (difficult to machine)

• Size compatible with existing AM machines

• Short run &/or quick turn applications

QUESTIONS