Printing for Aerospace ApplicationsInside 3D PrintingApril 12, 2016

Mark Walluk

Staff Engineer

Introduction

Goals of this presentation are

to:

• Explore benefits of 3D

printing through a case

study on unmanned

aerial vehicle (UAV)

applications

• Share findings from

mechanical and

metallurgical studies of

3D printed parts

ProX300 - DMLS

Tensile

Introduction

Summary

3D Design

Considerations

Material

Properties and

End Results

Intro

Introduction

Who are we and why are we presenting?

Rochester Institute of Technology

(RIT) is a large private university in

Upstate New York

Center of Excellence in Advanced

& Sustainable Manufacturing

• Responsible for outreach to

NYS companies on

sustainable manufacturing

and technology

COE-ASM: What do we do?

COE-ASM is dedicated to helping existing and emerging manufacturing companies bridge the gap between R&D and manufacturing implementation:

• Applied Research & Development

• Technology Validation and Deployment

• Product and Process Efficiency

• Workforce development

About COE-ASM

• Multi-disciplinary academic and applied research unit at RIT

• 118 staff engineers, technicians, faculty researchers, and funded students

• 225,000 sq ft of advanced manufacturing facilities and infrastructure, with 400-seat training facility

• $70M+ in manufacturing, equipment, labs & testbeds

We are able to assist through

Design

· Mechanical and electrical design and simulation

· Design for manufacturing

· Material selection/substitution

Prototype Fabrication

· Additive manufacturing in plastic and metal

· CNC fabrication equipment

· Electrical and mechanical testing and integration

· Linkage to industry (prototype and production)

Inspection & Validation

· 3D imaging and dimensional verification

· Material characterization & properties

· Performance and robustness evaluation

Digital Manufacturing & Product Realization Lab

One lab relevant to this presentation

3D Design

Summary

3D Design

Considerations

Material

Properties and

End Results

Intro

3D Printing for UAVs - A Case Study

High level objective – Aid startup company in development of

a new power system for unmanned aerial vehicles (UAV)

Requirements for small recon UAVs are

similar to other aerospace applications

Increase flight time through

• Reduced Weight

• Minimized Volume

• Increased Fuel Efficiencywww.benning.army.mil

Project at a High Level

A propane powered high temperature fuel cell system

was selected for fuel efficiency opportunities

However, the system would need to be compact:

Hence the investigation of 3D Printing

Breadboard

Compact Concept

Printing for UAV

The concept was to create a UAV component that

would combine functions of several parts to reduce

tubing, fasteners, gaskets, fittings, housing, etc.

Analysis

Finite element simulations were

performed; however questions arose on

design and properties:

• How do we design for metal 3D

Printing of fuel cell parts?

• What are the mechanical

properties of printed parts?

• Does print orientation and

pattern matter?

3D Design Considerations

Designing for metal 3D Printing requires special

considerations such as:

▪ Height to Width ▪ Min Angle

▪ Min Thickness ▪ Horiz Holes ▪ As-Built Dim.

▪ Sealing

Sealing

After several iterations, we found that Swagelok®

ferrules would seal gases at low pressures.

Final process conditions:

• Designed to nominal tube OD dimension

(e.g. ¼ inch)

• As-built outer diameter was

3% greater than design

• Used as-built tube roughness

(did not polish)

tube ferrule

Guidance

Our design guidance for assurance of

high quality metal parts:

50⁰ Minimum 4:1 Max Height to Width

Wall thickness of 0.06 inch for gas sealing

Water drop shape for near horizontal holes

(> ¼ inch)

Use as-built for ferrule seals

Imperfections

The final specimens had

printing imperfections

(700µm deep) along the +Z

direction normal to the print

plane

3D-Microscopy

Fine Features

One benefit of 3D Printing is the ability to create

fine features within the component.

Multiple internal Small holes,

0.020 inch diameter, were

created without the need for

machining

Summary

3D Design

Considerations

Material

Properties and

End Results

Intro

Material Properties

The direction and pattern type

of printing was studied for

effect on mechanical

properties

• Hex vs Normal

• Angle vs roll direction

HEX Pattern

15⁰ 45⁰

Note: default build

parameters, not optimized: 400W, 40μm

R

O

L

L

E

R

Static Properties

Several properties of polished tensile

specimens were analyzed; Avg. data:

TypeYield St. 2% (ksi)

Ult. St. (ksi)

Vickers Hardness

Porosity (%)

Wrought 151 156 361 0

Normal 45⁰

111 182 393 1

Hex 45⁰ 103 184 410 0.5

Hex 15⁰ 127 175 406 2

No Oxy in material during SEM/EDX scan

W P

Dynamic Properties near yield strength

Printed = 20,000 cycles at 100ksi

Wrought = 81,000 cycles at 150ksi

∆ Cycles

∆ Stress Mag 2400x

15⁰

Printed

Wrought

However, 3d printing provides its own solution

Research Opportunities

Opportunities for Improvement:

• Investigate machine parameters

(e.g. layer, powder size, laser

power)

•Post Processes

•Heat treat

•Hot Isostatic Pressing

•Ultra-sonic surf. Mod.?

•Shot peen?

•Etc?

Yadollahi, et. al.; “Fatigue Behavior of Selective laser

melted 17-4PH Stainless Steel”

Summary

3D Design

Considerations

Material

Properties and

End Results

Intro

Summary

Benefits of 3D printing include:

• The ability to integrate multiple components into 1;

reducing weight and volume

• Quickly realizing a physical

prototype from CAD

• Adding details otherwise difficult

with conventional manufacturing

Remember design considerations

and difference in material

properties

For more information:info@sustainability.rit.edu

Thank you

COE - Any opinions, findings, conclusions or recommendations expressed are

those of the author(s) and do not necessarily reflect the views of the NYS

Department of Economic Development (DED), unless otherwise directed by the

DED.

www.rit.edu/gis/cesm/