Impact of Friction Re

Technologies on Fuel 

Presented at the March 2009 Chicago Meeting of the ‘Society of Tribologists a

Engineers’ MeetingMarch 18th, 2009

George FenskeArgonne National Laboratory
Outline of Presentation

 Overview of Petroleum Consumption - How Much Do We  How Does Tribology (Friction and Wear) Fit Into the Equ

– If we get rid of all friction, how big of an impact will a 

engine have on petroleum consumption

– If We reduce friction by x%, how much petroleum ca

 What’s Being Done (Research) to Reduce Petroleum Co

Improve Energy Security?

 Examples of Tribology Research Activities at Argonne R

Transportation
World Energy Production & Consum

1 QUAD/yr ~ 0.5 MBBL/day

 World Energy Production (All Sources) 460 

 US Energy Production (All Sources) 72 Q

– 16% of World Production

 World Energy Consumption (all sectors) 463 

 US Energy Consumption (all sectors) 101 

– 22% of World Consumption

 World Petroleum Production 81 M

 US Petroleum Production 6.9 

– <9% of World Production

 World Petroleum Consumption (all uses) 85 M

 US Petroleum Consumption 21 M

– 25% of World Consumption

http://ww
US Energy Flow (2007) - 102 QUADs

 QUADrillion (1015) BTUs per year

 1 QUAD equivalent to 0.47 million bbl crude oil/day

– 39.82 QUAD Petroleum - 18 million bbl/day

http://www.eia.doe.
US Oil Consumption Increasing, Production D

Relying More & More on Imported Oil - Now ImApproximately 60 % of Oil

http://ww
Sources of Imported Oil

 Oil imported from a variety of countries, both OPEC an Political stability of oil partners of concern to long-term 

driving federal efforts to reduce our dependence on im

developing domestic supplies, alternative fuels, and epolicies.

http://ww
Majority of Oil Consumed by ON-ROAD Vehic

MBBL/Day for Cars, Light Trucks, and Heavy 
How Much of the 10-11 MBBL/day of Petroleum 

Road Vehicles is Lost to Friction? - More EnergFriction Than is Delivered to the Wheels

 Energy Map- Passenger Vehicle EPA Cycle

– Roughly 10% of energy input consumed by 

friction

– 1 million barrels/day lost to friction in 

transportation

Exhaust

35%

Engin

Other Engine Friction

0.4%

Piston Assembly

2.8%

Valve Train

1.3%

Bearings

1.0%

Seals

0.5%

Others

1.6%

Transmission

2.0%

Braking

2.0%

Axle

1.6%

Accessories

Oil Pump - 0.5%

Air Pump – 0.1%

Water Pump - 0.1%

Fuel Pump - 0.1%

Power Steering – 0.5%

Cooling Fan – 0.5%

Alternator – 0.5%

Viscous Loss – 1.35%

Friction Forces – 0.95%

Blowby – 0.5% 

15% of IMEP

(Indicated Mean Effective 

Pressure – HP normalized 

to engine displacement)
500

700900

11001300150017001900

0 500 1000 1500 2000

Load/IMEP (kPa)

Speed (rpm)

1 (52%)

2 (3%)

3 (4%)

4 (15%) 5 (8%)

6 (6%) 7 (8%) 8 (5%)

Weighting factor

Detailed Studies of Heavy-Truck Friction Losses BaseModels of Boundary and Hydrodynamic Friction PrediLowering Boundary Friction and Lubricant Viscosity o

•Fuel inje

* in

 FMEP calculated at 8 different modes and 

weighted to predict effect on fuel consumption for a HD driving cycle

FCSF = 

(Fuel Consumption Scaling Factor)

IMEP + ΔFMEP

IMEP
Role of Boundary and Hydrodynamic Lubricatio

- Tribological System

 Different regimes of lubrication 

depending on the degree of contact between sliding surfaces

 Boundary lubrication 

characterized by solid-solid contact – asperities of mating 

surfaces in contact with one another

 Contrast boundary lubrication 

with full-film lubrication in which mating surfaces are separated by a film.

 In between, mixed lubrication 

occurs.

Boundary Lubr

Viscosity 

Friction Coefficient
Boundary and Hydrodynamic Friction: Model Im

FMEP and Wear Severity

 Total FMEP is the sum of the Asperity friction and the hydrodynamic friction

– Boundary FMEP decreases with increasing lubricant viscosity –

shifting from BL 

– Hydrodynamic FMEP increases with increasing viscosity

Piston FMEP versus Viscosity Grade

05

10152025

10 20 30 40 50

SAE Viscosity Grade

FMEP (kPa)

No Treatment TotalEst 30% Reduction TotalEst 60% Reduction Total90% Reduction TotalHydrodynamicAsperity / No TreatmentAsperity / Est 30%Asperity / Est 60%Asperity / 90%

Normalized P

0.00.51.01.52.02.53.03.54.04.5

0 10 

SAE 

Relative Wear Load

Viscous

FMEP

Asperity

FMEP
Friction Losses are Greatest (Relative to Engi

Low Speeds and High Loads - Forward-Predi

 Under idle conditions, over 50 % of energy consumed to 

friction (boundary and viscous) - pumping losses accou

40 Weight Oil71 kPa FMEP compared to 617 kPa IMEP

Ricardo 

750 960

1170

1590

1800

1683

983

325

104

0

10

20

30

40

50

60

FMEP (% IMEP)

Speed (rpm)

IMEP (kPa)

FMEP As a Fraction of IMEP

40 wt, 0% Reduction

Weighted Avg. - 11.6%

71 kPA FMEP: 617kPA wt'd IMEP

750 960

117

0

10

20

30

40

50

60

FMEP (% IMEP)

Speed (rpm)

30 % reduction in FMEP (71 to 50 kPa)

21 kPa reduction in FMEP represents 3.5% of IMEP - or an increas

20 Weight Oil, 9050 kPa FMEP com
Modeling the Impact of Friction on Fuel Effi

Identifying Critical Components - HD Diese

 Prediction/Modeling of Fuel Savings

– Systematic studies on the effect of 

boundary friction and oil viscosity on fuel efficiency

– Up to 1.3 % fuel economy improvement 

by low friction additives and/or coatings

– 3-4% fuel economy improvement by 

reducing boundary friction and reducing 

oil viscosity

– Additional 2-4% fuel economy gains in 

transmission and differential/axle

Piston Rings and Skirt: Impact of Reduced Asperity Friction on Fuel Savings (gals) 

@ 1000 hrs Operation

-100

-50

0

50

100150200250300

0 10 20 30 40 50 60

SAE Lubricant Grade

Gallons of Fuel Saved per 1000 

Hours Operation

Baseline Friction - 0% Reduction30% Asperity Friction Reduction60% Asperity Friction Reduction90% Asperity Friction Reduction

SAE V

-6%

-4%-2%

0%2%4%

0 10 

Predicted Change in Fuel Consumption

0% Re30% R60% R90% R
Summary

 10 -12 Million barrels of oil consumed per day in US fo Only 10% of fuel is actually required to ‘move’ the veh

– Tires/rolling resistance– Aerodynamic drag

 Approximately 10 % consumed by engine friction Another 4-6 % consumed by transmission/drivetrain lo

– Gears. Seals, Churning

 Reducing boundary (asperity) friction by itself can be b

 Reducing viscosity by itself is limited to 20 WT before 

friction increases (1/2%)

 Reducing boundary/asperity friction enables the use o

fluids and even greater fuel savings (3-5 %)

– However - lower viscosity fluids will result in highe

thus require more wear resistant/durable materials
Sources for Further Information on Departm

and Argonne Activities on Transportation:

http://www.transportation.an
Sources for Further Information on Departm

and Argonne Activities on Transportation:

http://www1.eere.energy.gov/vehi
Argonne Tribology Activities - Reducing Fric

Improving Durability & Reliability

 Modeling

– Collaborations with Ricardo to model impact of friction on f– Importance of boundary layer friction in it’s role to enable th

lubricants

 Advanced Materials & Coatings

– Over 20 years of research focusing on the development of 

materials for TRIBOLOGICAL APPLICATIONS

• High temperature solid-film lubrication of ceramics, Low 

composites, Ultralow friction DLCs, Superhard Nanocombased coatings

 Advanced Additives

– Layered film additives, nano-additives 

 Characterization & Testing

– Room temperature to 1000C, unidirectional & reciprocating 

conformal contact, dry (vacuum, inert, hydrogen, methane) 

– Advanced characterization (optical, electron, ion beam ana

morphological, microstructural, and chemical information in 
Pure MoN (Typical of 

All CurrentHard Coatings)

From columnar to nearly-featurless morph

1.2% Cu

MoN with

0.6% Cu

Coating Design, Development, and Charac

Substrate

NanoGrains

After acid etching After ion etching 

Grain size: 50-70 nm

Erdemir, Eryilm
0

0.020.040.060.08

0.1

0.12

0 5 10 15

KTF 210

Depth

Load (mN)

E/(1-v2) = 401.23 +/- 17.18 (GPa)Hardness = 67015 +/- 4683 (N/mm2)Wp = 0.14 nJ (%15)We = 0.79 nJ (%85)

Sputter ion plating system

Hardness Behavior

Mechanical/Tribological Characterization

Tunable between 30 to 60 GPa

Note that coating fractures, but do not delaminate, “good sign for strong adhesion”

Mercedes Adhesion Test

Rockwell C

Indent

Superhard Coating vs 

20 N load, 10 rpm , 

0

0.020.040.060.08

0.1

0.120.140.160.18

0.2

0 200 400 600 

Dis

Friction CoefficientMo

Polished with 

Erdemir, Eryilm
Hydrogenated DLC (N3FC) or Hydrogen Free a-C Deposition:N3FCMagnetron Sputtering PVDGas Mixtures:CH4 and Ar gas mixture for N3FC

Carbon target for deposition and plasma enhancementC Target Power : 1000-3000 WPlasma Booster is used (80-100 V)Pulsed DC BIAS350 KHz, -35 VThickness : 10 nm - 2 μmProcess Temperature : RT-150o CRoughness of Coated surface:Sa : 49.3 nm

Deposition of Hydrogenated DLCs b

Ar

CH4

Eryilmaz, Erdem
Argonne’s Superlow Friction or Nearly Fricti

(NFC) Films

NFC Coated Lead Screw

US Navy

NFC Coated Hydrolic Pump 

CAT

N

NFC Coated Test Parts for Potential gearbox Applications

Eaton

E
μm BA nm BA

Develow-and addiinternanonm-ssuspmeta

Steel Ball Against Mg in 

Pure PAO and in Boroncontaining Pure PAO

Lubricants & Additives

Erdemir, Eryilm
Impact of Additives on 

Scuffing Performance

 Investigation of commercial 

additives to increase scuffing performance of military lubricants under severe lubrication environments

1026

616

490

649

431

187

1103

10211059

952933

12031047 1

0

400800

12001600

15W40 ‐ 750 15W40 ‐ 1000 15W40 ‐ 1500 RHT240 ‐ 750 RHT240 ‐ 1000 RHT240 ‐ 1500

15W40:Boric Acid 25:1 15W40:Boric Acid 10:1 15W40:Boric Acid 5:1 15W40:TCP 25:1 15W40:TCP 10:1 15W40:TCP 5:1 15W40:BN 25:1 15W40:BN 10:1 15W40

Scuffing Load (N)

Run 1 Run 2 Run 3 Run 4 Average

Avg. Scuff Load for 

15W/40 SK @ 1000 rpm

•Blue – Load•Red – Frict•Green – Blo•Brown – Ri

•Micro-Sc
BL

RO

Sliding direction

Slid

Uniformity in direction of sliding

Ajayi, Lorenzo‐

OPTICAL MICROSCOPY - Wear track shows fbright white spots - tribo-film formation/remo
perpendicular 

PROFILOMETRY - provides detailed quantitaon tribo-film formation - non-uniform distribu

Ajayi, Lorenzo‐Martin, Erck ‐ Argonne
FIB Procedure - ion-beam ‘back-hoe’ to harve

cross-sections for detailed TEM characteriza

Ajayi
A

TEM of FIB specimen- texturing - sub-surface structure & composition of tribo-film

tribo-film sub-surface grain 

refinement
Surface Characterization - TOF-SIMS

 Application of surface 

sensitive techniques to surface film chemistry

– DLC– SHNC

Sulfur

Eryilmaz ‐ Argo
Summary

 US depends on energy - 25 % of energy consumed us

transportation

 More energy is lost to friction than is delivered to the w

– 10% of energy is lost to friction

– Equivalent to 1-1.5 MBBL/day

 Lowering lubricant viscosity by itself in not sufficient - 

boundary/asperity friction and lubricant viscosity togetsignificant energy savings
Acknowledgement

 US Department of Energy - Energy Efficiency & Renew

Vehicle Technologies

 Argonne National Laboratory - UChicago, Argonne LL

 Tribology Section

– Ali Erdemir, Layo Ajayi, Robert Erck, Osman Eryilm– Cinta Lorenzo-Martin, Nick Demas, .....– Guldem Kartal, Christine Matta– Ashlie Masoner, Qunfeng Zeng, .....