©2009 Rolls-Royce plc The information in this document is the property of Rolls-Royce plc and may not be copied or communicated to a third party, or used

©2009 Rolls-Royce plcThe information in this document is the property of Rolls-Royce plc and may not be copied or communicated to a third party, or used for any purpose other than that for which it is supplied without the express written consent of Rolls-Royce plc.This information is given in good faith based upon the latest information available to Rolls-Royce plc, no warranty or representation is given concerning such information, which must not be taken as establishing any contractual or other commitment binding upon Rolls-Royce plc or any of its subsidiary or associated companies.

IMFAIR Conference 10-11th June 2009

The Future of Design for Surface Engineering in Aerospace Applications

The Future of Design for Surface Engineering in Aeroengine Applications

D S Rickerby

Rolls-Royce plc

Derby, UK



Contents

The need for Advanced

Materials

The move from reactive to

proactive design of Material

Systems. Compressor

Turbine

Summary and Future

Opportunities



Materials Making the Difference

“Developments in advanced materials, more than anything else, have contributed to the spectacular progress of the aero gas turbine”

Stewart Miller Director-Engineering & Technology 3rd Finniston Lecture 1996



The Drivers

Strength

Temperature capability

Density

Cost

Time

PredictiveCapability

Per

form

ance

Saf

ety

Saf

ety

NoiseNoiseEmissions

EmissionsCostCost

Weight

Weight



The Drivers

Per

form

ance

Saf

ety

Saf

ety

NoiseNoiseEmissions

EmissionsCostCost

Weight

Weight

Over the last 35 Years

• Turbine Entry Temperatures have increased by 500C

• In civil applications engine thrust has increased by a

factor of x4

• The specific fuel consumption has reduced by

ca 35 %

Surface Engineering usage has increased from 25 to

greater than 50 % for turbine components



Trends in Materials Usage

Nickel

Titanium

Steel

Aluminium

Carbon composites

6060

5050

4040

3030

2020

1010

Wei

ght

Per

cent

Wei

ght

Per

cent

19701970 19801980 1990199019601960 20002000



Titanium Fan Blade Snubber

Tungsten carbide/cobalt coatings reduce sliding/impact wear



Early Benefits of Surface Engineering – Corrosion Protection

Performance penalty of ca. 5% at take off which approached the limit of acceptability for a twin engined turboprop aircraft

Increase in specific fuel consumption of up to 2% which represented a significant cost penalty for the operators.

Surface engineering became an essential and very competitive issue in the aerospace industry.

Service run Nimonic 108 HPTB’s



Reactive versus Predictive Design

Re

so

urc

es

Re

qu

ire

d

Re

ve

nu

e G

en

era

ted

Revenue predictive design

Revenue reactive design

Launch Launch Time

Current and Future Designs- Predictive Design- Early Problem Identification- Solution when costs are low

Early Engine Designs- Reactive Design- High Costs



The aero engine market has never been more competitive Mature industry, limited scope for technology advancement Product differentiation is by being

First to produce a suitable engine for the market Best specification to the customer Engine development cycle in line with that of the civil airframers.

Four stage life cycle which covers all activities from the generation of the initial product concept and business case through to product entry into service and beyond into its service life.

Use of generic designs to existing and new products using proven technology.

Capability acquisition activity to secure future technology requirements

Product Definition Lifecycle



Product Definition LifecycleBusiness Led

Stage 1Product Planning

Stage 2Full Concept

Definition

Stage 2Full Concept

Definition

Stage 3Product

Development

Stage 3Product

Development

Stage 4In-Service

Management

Stage 4In-Service

Management

Capability AcquisitionMCRL/TRL

Capability AcquisitionMCRL/TRL

Preliminary Launch

FullLaunch

ProductDelivery

Development (1-4) Pre-Production (5-6) Production (7-9)



The Problem of Erosive Attack

Erosion can be caused by sand ,dust and even water.

It introduces uncertainty into any lifing assessment.

Severe erosion is generally confined to operation in specific flight areas ie desert type conditions.

The change in aerofoil geometry and liner dimensions will eventually impact upon engine performance.

The requirements for the coatings defined as:

No reduction in mechanical properties Effective over a range of conditions Retain component aerodynamics



Erosion Coating Service Experience These early coating systems developed for use as hard wear resistant layers for machine

tools. Service return of blades showed deep scoring from impact of large particles causing local

break up of coating. Single layer systems do not give the required extension in life. Need to develop coating systems tailored to their environment to give effective protection

against erosion.



“Engineered” solution to erosion protection

Multi-layer coatings deposited using PVD methods to increase erosion performance – nano engineering

Impact on mechanical performance minimised

Capability being developed for advanced engines

W

NiAl



Multi-layer concept - GE T64 sand erosion tests

Service Performance of Multi-Layer Coatings

Description Non-Coated CoatedRate of premature engine removal due to erosion 20-45% 0%Rate of blade/vanes rejected due to erosion 70-80% 2-3% (mostly due to FOD)Engine performance debit at overhaul 10-30% <3%

Source: MDS-PRAD

Documents

©2009 Rolls-Royce plc The information in this document is the property of Rolls-Royce plc and may not be copied or communicated to a third party, or used