MDEC 2009

S5P2- 1

Development of Aluminium Alloys for High Temperature Applications in Diesel Engines

- Overview of selected research activities -

CANMET Materials Technology Laboratory, Ottawa, Canada(Program: Advanced Structural Materials for Next Generation Vehicles)

MDEC Conference 2009, Sheraton Parkway, Toronto North, Richmond Hill, October 4 - 9, 2009

W. Kasprzak, M. Sahoo, D. Emadi

CANMET First Page-Pictures!!!

Introduction Emissions in automotive sector

Strategies for emission reduction

Vehicle weight reduction

Innovations in manufacturing processes

Existing Al alloys for diesel engine components and requirements Alloy survey

Performance challenges

Al Alloy development activities at CANMET-MTL

Energy efficient heat treatment strategies

New trends for engine casting’s performance improvement

Presentation Overview

MDEC 2009

S5P2- 2

Source: Canada’s GHG Emissions from Transportation in 2004

CO2 Emissions Per Sector Introduction

0

20

40

60

80

100

120

140

160

180

200

2201990 2000 2010 2020

CO

2-E

qu

ival

ent

(Meg

a t)

Res

iden

tial

Com

mer

cial

Ind

ust

rial

Ele

ctri

city

G

ener

atio

n

Fos

sil F

uel

P

rod

uct

ion

Non

-En

ergy

Tra

nsp

orta

tion

Sector

K Transportation sectorHeaviest contributor to GHG emissions

Source: NRCAN, Canada’s Energy Outlook: 1996 - 2020

K Passenger vehicles + light trucks~55% of transportation emissions

Off-Road Gasoline, 0.2%

Off-Road Diesel, 1.9%

Domestic Aviation, 4.6%

Railways, 3.6%

Domestic Marine, 3.9%

Heavy-Duty Gasoline Vehicles, 2.5%

Other, 1.6%

Light-Duty Gasoline Vehicles, 29.4%

ty Gasoline s, 25.8%

y Diesel 26.5%

Heavy-Duty Diesel Vehicle 26.5%

Light-Duty Gasoline Trucks, 25.8%

Light-Duty Gasoline Vehicle 29.4%

CO2 Emissions for Various Vehicle Concepts and Car Makers

Source: RHEINFELDEN Company, 2008

Introduction

CO2 Emissions per Region

Auto manufacturers

CO

2em

issi

on, g

/km

CO2 Emissions per Different Car Concept

Hybrid-Honda Insight

Hybrid-Toyota Pirus

Light weight diesel car

Light weight petrol car

Heavy diesel car

Heavy petrol car

Sports Utility Vehicle

CO2 Emissions g/km

MDEC 2009

S5P2- 3

Vehicle Weight Reduction for Improved Fuel Efficiency and CO2 Reduction

Introduction

Source: U.S Environmental Protection Agency (http://epa.gov)

Mileage of cars and light trucks sold in US must rise

from current 25 to 35.5 mpg by 2016.

Will be not enough to bring US in line with vehicles

sold now in Japan and Europe.

10

15

20

25

30

35

40

45

50

55

2000 3000 4000 5000 6000

Intertial Weight Class (Pounds)

Mile

s p

er G

alllo

n

Cars

SUV's

Pickups

K Approx. 10% drop in weight

K 6-8% better fuel economy

Introduction

Major Activities:

Application of light weight alloys,

Innovations in manufacturing process,

Component design.

Reducing the weight of vehicle by 100kg results in:

Reduces fuel consumption by 0.3 to 0.5l/100km,

Extends the cruising range by 7.5%,

Allows to reach 100km/h six (6) meters sooner,

8 to 11 less grams of hydrocarbon emission every kilometre,

Active and passive safety improvement:

Quicker reaction to driver’s inputs,

Brings less energy to a crash.

Activities with Major Impact on Weight Reduction and CO2 Emissions

MDEC 2009

S5P2- 4

Activities with Major Impact on Weight Reduction and CO2 Emissions - cont.

Introduction

1. Application of light weight alloys

Chassis and body

K 100kg weight reduction

K 2-3% better fuel economy

K 3.5g/km CO2 reduction

Steel baseline design79 Parts & 84.3 kg

Magnesium design35 Parts & 46.1 kg

38.2 kg mass reduction (45%) 44 part reduction (55%)

Source: US-Canada-China Collaborative R&D Project (MFERD), CANMET-MTL, 2009

Activities with Major Impact on Weight Reduction and CO2 Emissions - cont.

Introduction

1. Application of light weight alloys

Powertrain

K 30% Engine downsizing

K 10-15% less engine weight

K10-20 % less CO2 emissions

Heat resistant Al Cylinder Head (Al-6%Si-3%Cu alloy)

Liner-less Cylinder

Cast-in Iron Cylinder Liners 3.0l

V6

Eng

ine

Blo

ck (

Al-

Si-

Cu

allo

y)

Forged Al Piston (Al-11%Si-3%Cu-0.5%Mg alloy)

MDEC 2009

S5P2- 5

HPDC Casting process

Introduction

Heat treatment Machining Honing

3%Machining

0.2%Casting

96.8%T6 HT

Activities with Major Impact on Weight Reduction and CO2 Emissions - cont.

2. Innovations in Manufacturing Process – Energy Efficient Heat Treatments

ProcessDuration, min

Improvement, %Existing Revised

Vacuum HPDC 1 1 N/A

Heat treatment (T6) 480 175 63

MachiningEngine block

Cylinder bore (honing)

15.513.5

2

15.513.5

2

N/A

W. Kasprzak, et. al., “Development of Energy Efficient Heat Treatment Processes for Light Weight Automotive Castings”, 25th ASM Heat Treating Society Conference, IN, USA, p. 1-10, 2009

Upcoming Diesel Cars in 2009/2010

BMW 335d Twin-turbo 3.0 liter in-line engine 23 mpg in the city and 33 mpg on the highway

Acura TSX Diesel New 2.2 liter i-DTEC four-cylinder clean diesel engine

Volkswagen Jetta TDI 2.0 liter four-cylinder turbo-diesel engine

Honda Accord Tourner Concept 2.2 liter i-DTEC diesel

The i-DTEC technology is aimed at meeting Europe’s tougher Euro 6NOx regulations in 2014

Introduction

http://www.autotropolis.com/wiki/index.php?title=Upcoming_Diesel_CarsL Good evidence for alloy development activities

MDEC 2009

S5P2- 6

Components Engine Block Cylinder Head Piston

Alloy System Al-Si-Mg-(?)

Al-Si-Cu-(?)

Al-Si-Mg-(?)

Al-Si-Cu-(?)Al-Si-Cu-Ni-(?)

Operating Temperature (oC) 135 250 400

Operating Pressure (bar) - >180 -

HCF (MPa) 180 140 >200

Creep 0.1/100 - 44 -

SDAS (μm) 20 20 -

Process LPSP, HPDC SPM SPM, Forging

LPSP - Low Pressure Sand Package

SPM - Semi-Permanent Mold

HPDC - High Pressure Die Casting

Al Castings for Engine Applications in Passenger Vehicles

Limitations: Elevated operating temperature and internal pressure disqualify existing Al alloys forsmall, turbocharged, energy efficient automotive engines

Performance Challenges

The aluminum alloys claimed to be used for gasoline anddiesel engine cylinder heads:

Category 1: Al-Si-Mg alloys (ex: A356, A357)

- (good ductility, lack of strength >250oC)

Category 2: Al-Si-Mg-Cu alloys (ex: A356 + 0.5% Cu)

- (good ductility, retaining strength between 200-250oC)

Category 3: Al-Si-Mg-Cu alloys with Mn, Zr, V, Ti and Cr

(ex: A356+1%Cu+0.15%Zr+0.15%Cr and A319+0.15%Mn+0.25%V+0.15%Zr)

- (lower ductility, higher YS and creep at 250oC)

R.Fuoco, M.F.Moreira, Fatigue Cracks in Aluminum Cylinder Heads for Diesel Engines, AFS 2009, 09-117

Existing Alloys

Alloy Chemistries used for High Temperature Powertrain Applications

(Passenger Vehicles)

Current

Future

MDEC 2009

S5P2- 7

Alloy Chemistry Survey for Diesel Cylinder Heads (Passenger Vehicles)

Product Alloying Elements, %

Si Cu Mg Zn Fe Ti Mn Ni Cr Sn Pb Sr V Zr

A 6.4 3.2 0.22 0.52 0.52 0.15 0.40 0.032 0.028 0.007 0.074 0.01 - -

B 5.5 3.2 0.19 0.035 0.29 0.12 0.34 0.017 0.010 0.005 0.01 0.01 - -

C 5.3 3.4 0.14 0.27 0.56 - 0.56 0.023 0.03 0.02 0.02 - - -

(Europe 1998 Model)

BA

(Europe 2003 Model) (Asia 2005 Model)

C

L Strong popularity of conventional alloys (Al-Si-Cu-Mg)

Existing Alloys

Development of the Al Alloy Chemical Compositions

R&D Activities

Si Cu Mg Fe Sr Ni Zr Ti V Sc

7→20 0.1 →4 0.1 →1 0.1 → 0.4 0 → 0.2 0 → 0.5 0 → 0.4 0 → 0.2 0 → 0.4 0 → 0.4

Al Alloy chemistries under evaluation based on 356, 319, 390 grades with various addition levels

L Only compromise will lead to optimum alloy chemistry

Casting High Temperature Performance

Mechanical Testing

Thermo/Physical Testing

Tensile Creep Fatigue

Thermal Analysis Dilatometry Electrical

Resistivity

MDEC 2009

S5P2- 8

Mechanical Testing (Tensile at 25-250oC)

Mechanical Properties

Testing temperature, oC

UTS, MPa

50

100

150

200

250

300

0 50 100 150 200 250 300

N6132A N6132B N6133A N6133BN6173A N6174A N6174B N6174CN6187A N6187B N6187C N6216AN6216B N6216C N6217A N6217BN6217C N7081A N7081B N7081CN7090A N7090B N7090C N7091AN7091B N7091C

HT: T6

50

100

150

200

250

300

0 50 100 150 200 250 300

N6132A N6132B N6133A N6133BN6173A N6174A N6174B N6174CN6187A N6187B N6187C N6216AN6216B N6216C N6217A N6217BN6217C N7081A N7081B N7081CN7090A N7090B N7090C N7091AN7091B N7091C

HT: T6

Testing temperature, oC

YS, MPa

- Proper development of alloy chemical composition has an significant effect on mechanical properties at room and elevated temperatures

- Increased Cu has a predominant effect on elevated mechanical properties up to 250ºC.- Effect of Zr, V, Ti overlaps with Cu, Mg additions

Testing temperature, oC

E, %

YS,

MP

a

T6:

ST

@50

5ºC

/9h

rs+

AA

@25

0ºC

/100

min

s

UT

S, M

Pa

-3% Cu

-2% Cu

-1% Cu

-0.5% Cu50

100

150

200

250

300

350

0 50 100 150 200 250 300

-3% Cu

-2% Cu

-1% Cu

-0.5% Cu

Mechanical Properties

Mechanical Testing - cont.(Tensile at 25-250oC)

MDEC 2009

S5P2- 9

High Temperature Performance Assessment (Creep)

Stress levels for 0.1% elongation after 100hrs exposure for 356 based alloys tested in T7 condition

AlloyHardness (HR15T)

Before Creep After Creep

A 58 61

B 56 57

C 80 71Fracture surface of

356+1.0Cu+Zr+V+Ti alloy

356+0.5Cu+Zr

365+0.5Cu+Zr+V+Ti

Str

ess,

0.1/

100,

MP

a

365+1.0Cu+Zr+V+Ti

L Additions of Zr, V, Ti improves creep performance due to formation of dispersoid phase

Mechanical Properties

Microstructure Evaluation in the As-Cast Condition

Time, s

Tem

per

atu

re, º

C

Solidification curves (1.0ºC/s)

#1

Solidification

#2

#3, 4

Thermal Characteristics Temp., ºCEffect of Zr/V/Ti

Melting Cycle

Beginning of melting 507.6±0.1 No effect

End of melting 648.9±2.6

Melting Range 141

Solidification Cycle

#1 - Liquidus Temp. 622.5±0.2

#2 - Nucleation of Al-Si 576.3±0.5 No effect

#3 - Nucleation of Cu phases 545.6±0.8 No effect

#4 - Solidus temp. 503.4±1.5 No effect

Solidification Range 119

L Zr, V, Ti levels below peritectic point to avoid nucleation of primary compounds.

Hea

tin

g /C

ooli

ng R

ate,

ºC

/s

Temperature,ºC

#2

#1

#4

Solidification range

#3

Alloy: 356+0.5Cu+Zr/V/TiBSE

BSE

Ti

VZr

Si

Mic

rost

ruct

ure

An

alys

is, S

EM

/BS

E/M

ap

The effect of Cu, Mg additions on incipient melting temperature

L 0% Mg - higher solution & better homogenization

Cu Mg Zr, V, Ti

Microstructure Analysis

MDEC 2009

S5P2-10

W. Kasprzak, D. Sediako et al., Characterization of Hypereutectic Al-Si Alloys using In-Situ Neutron Diffraction and Thermal Analysis Techniques, TMS 2010

Alloy Phase Identification - Neutron Diffraction during Solidification Process

1

2

3

4

Solidification CellNRU Atomic Reactor

Thermal-neutron spectrometers

NRU Reactor (Chalk River, Canada): Thermal

neutron source (120MWth), Medium flux

(~3 x 1014/cm2/s)

Neutron diffraction spectrum for Al-18%Si alloy obtained during solidification with ~1oC/s

L Improved signal resolution for more detailed solidification analysis

Alloy: Al-18%Si

Inte

nsi

ty

Microstructure Analysis

Effect of Alloy Chemistry on Casting Dimensional Stability

Thermo-physical

Properties

Heat treatment needs to be optimized to control stress development

Tem

per

atu

re, º

C

Len

gth

Ch

ange

, dL

, μm

Time, min

Alloying Element Thermal Expansion

Cu, Mg, Sc, Cr

Zr, V, Ti TBD

Len

gth

Ch

ange

, dL

μm

Temperature,ºC

Length change between 100-500oC for various alloy chemistries

Heat treatment crack between cylinder bores

L Minimized residual stress for improved fatigue performance

Zr

2.06 (Å)

Sc

1.84

V

1.35

Ti1.76

Cr

1.66

Cu

1.45

Mg

1.45

Al

1.18

Si1.11

Zr

2.06 (Å)

Sc

1.84

V

1.35

Ti1.76

Cr

1.66

Cu

1.45

Mg

1.45

Al

1.18

Si1.11

MDEC 2009

S5P2-11

Effect of Alloy Chemistry on High Temperature Performance

0.032

0.037

0.042

0.047

0.052

0.057

0.062

50 100 150 200 250 300 350 400 450

N6132A (0.5Cu-0.2Mg-0Zr-0.1Ti-0V)N6133B (0.5Cu-0.2Mg-0.2Zr-0.24Ti-0.15V)N6174C (0.86Cu-0.47Mg-0.17Zr-0.17Ti-0.19V)N8105 (1.12Cu-0.42Mg-0.23Zr-0.2Ti-0.2V-0.013Cr)N8108 (3.5Cu-0.39Mg-0.17Zr-0.17Ti-0.17V-0.01Cr)N8111 (1.0Cu-0.39Mg-0.19Zr-0.18Ti-0.17V-0.15Cr)N8007A (1.07Cu-0.6Mg-0.26Zr-0.2Ti-0.18V)N8007C (0.98Cu-0.58Mg-0.1Zr-0.17Ti-0.12V-0.18Sc)

Fir

st D

eriv

ativ

e, d

L/d

t, μ

m/s

Temperature,ºC

Properties Degradation

Safe Operation

Time, s

Tem

per

atu

re, º

C

Len

gth

Ch

ange

, dL

-50

50

150

250

350

450

550

0 5000 10000 15000 20000 -20

0

20

40

60

80

100

120

140T, ºCdL, μm

Heat Treatment simulation using Quench Dilatometer

Over-aging temperature varies between 210-360oC depending from alloy chemistry

AlloyingElements

Cu

Mg

Ni

Zr

V

Ti

Sc

Alloy: 356 base + Cu, Zr, V, Ti, Sc

In-Service Assessment

L Effect of individual alloying elements on over-aging

temperature - TBD

0.027

0.029

0.031

0.033

0.035

0.037

0.039

0.041

0.043

0.045

0.047

100 150 200 250 300 350 400 450 500

Al-Si Al-Si+Cu Al-Si+Cu+Mg

Temperature, oC

Fir

st D

eriv

ativ

e, d

L/d

t, μ

m/s

Si Cu Mg Zr/V/Ti ?

Effect of Alloy Chemistry on High Temperature Performance – cont.

11.5K

11.5K

#1: MgSiCu

#1

#2

Al

Be

MgSiCu Cu

Cu

#2: AlSiFeCu

Al

Si

FeMn

Ni

FeNiMn

Cu

Alloys: Al-Si, Al-Si-Cu, Al-Si-Cu-Mg

In-Service Assessment

MDEC 2009

S5P2-12

Energy Efficient Heat Treatment for Diesel Cylinder Head

Heat Treatment

Development

UT

S, M

Pa

Fat

igu

e st

ren

gth

, MP

a

Tem

per

atu

re,o C

AA:220C/2hrs

ST:495oC/8hrs

AA:200C/2hrs

ST:525oC/2hrsST:505oC/1hr

Time, hrs LOM micrographs (100x) of the 319 alloy heat treated test sample (T6M)

L Potential for improved fatigue performance:- Two-step solution treatment- Interrupted quenching - Mild quench rate (5ºC/s 525-200)

Alloy: 319 (Al-7%Si-3%Cu-0.3%Mg) Alloy: 319 (Al-7Si-3Cu-0.5Mg)

Acknowledgments

Government NRC-CNRC, Chalk River, Canada NRC-CNRC, Ottawa, Canada

Academic University of Windsor, Windsor, Canada Ryerson University, Canada

Industrial NEMAK of Canada Corporation, Canada Yamaha Motor, Japan Nissan Motor, Japan

The testing was funded by Program on Energy R&D (PERD) office of NaturalResources Canada.

The authors would like to acknowledge the following individuals andorganizations:

F. Fasoyinu, L. Whiting, C. Bibby, B. Voyzelle, R. Zawadil. M. Aniolek ofCANMET-MTL and Zhoutang Deng from McGill University.