The Advantages of Using Extrusions to Solve Thermal Management Challenges

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The Advantages of Using Extrusions to Solve Thermal

Management Challenges for the Automotive Industry

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This webinar will be available afterwards at www.designworldonline.com & email

Q&A at the end of the presentation

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Before We Start

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Mary GannonModerator

Design World

Stephen Jackson Business Development

Mgr., TM ProductsSapa Extrusions NA

The Advantages of Using Extrusions to Solve Thermal Management Challenges for the Automotive Industry

ADVANTAGES OF USING EXTRUSIONS IN THE AUTOMOTIVE INDUSTRY TO

SOLVE THERMAL MANAGEMENT CHALLENGES

JASON WEBER & STEVE JACKSONNOVEMBER 3, 2015

ADVANTAGES OF USING EXTRUSIONS IN THE AUTOMOTIVE INDUSTRY TO SOLVE THERMAL MANAGEMENT CHALLENGES

AGENDA

Who is SAPA

Why Aluminum to Lightweight Vehicles and EV’s

Designing Thermal Extrusions

Extrusions versus Castings

Friction Stir Welding (FSW) of Extrusions

Module Heat Sinks

Extruded Cold Plates

Summary

SHAPING A SUSTAINABLE FUTURE THROUGH INNOVATIVE ALUMINUM SOLUTIONS

Precision tubingProfile-based building systemsValue-added profiles

Present in 40countries

100+ production units

5 business areas: Profiles Europe, Profiles Americas, Profiles Asia, Buildings System, Precision Tubing

~$8.5 billion sales Worldwide$2.4 billion sales America’s

SAPA IN FIGURES

World leader in aluminum solutions

23,000employees worldwide, 6,500 in Americas* 2011 pro-forma

GLOBAL APPLICATION DEVELOPMENTSapa Extrusions’ central product development resource. The team supports customers and regional Sapa resources in developing innovative solutions and products.

Key competencies Aluminum Extrusions Product Design & Optimization Simulation & Analysis Project Management Technology & Knowledge

Transfer

Product expertise Renewable Energy Thermal Management LED Thermal Solutions Marine Engineered Products

LOCAL PRESENCE, AROUND THE WORLD

SAPA IN NORTH AMERICA

Yankton, SD

Portland, OR

City of Industry, CA

Spanish Fork, UT

Burlington, NC

Connersville, IN

Mountain Top, PA

Mississauga, ON

Montreal, QC

Elkhart, IN Cressona, PA

Gainesville, GA

Delhi, LA

Phoenix

St. Augustine

Sidney, OH

KalamazooNorth Liberty, IN

Belton

Toronto, ON

Magnolia, AR

Monett, MO

Sapa shall offer the market innovative, value-enhancing solutions based on profiles and strip in the “green” and lightweight material aluminum.

Sapa shall be perceived as the most attractive partner through a combination of innovation, business know-how and cost effectiveness.

OUR MISSION & VISION

HYBRID THERMAL MANAGEMENTE-Vehicle thermalmanagement

LED Lights

Capacitor Housing(Thermal & Structural)

(Thermal)

(Structural)

(Thermal & Structural)



ALUMINUM EXTRUSIONS Material Advantages Process Advantages

Recyclable & Non-toxic

Lightweight

Strong

Corrosion resistant

Thermally conductive

Reflective

Electrically conductive

Non-magnetic

Non-sparking

Attractive

Finish Options

Virtually Seamless

Complex integral shapes

Easily assembled

Weldable

Machinable

Cost-effective

Short lead times

WHY COOLING ? HEAT IS THE ENEMY OF ELECTRONICSPerformance: Functional operation of device

Reliability: Temperature dependency of failures

Integrity: Structurally sound and mechanically strong

HEAT is the ENEMY of Electronics

Lack of Strength is the ENEMY of Shock & Vibration

Cost is the ENEMY of Everyone

Aluminum Extrusions can be the SOLUTION

ALUMINUM EXTRUSION SOLUTIONSAluminum Extrusions for Air Cooling

Modular Heat Sinks for High-Fin Ratio requirements

Liquid cooler for power electronics (IGBT, control unit, inverters, converters) and electric motors

Battery enclosures for structural & thermal management

Light-weight parts to light-weight the vehicle

THERMAL CONDUCTIVITY OF ALLOYSTherm al conductivities

0

50

100

150

200

250

pure aluminium extrude A l-alloys cast A l-alloys

ther

mal

con

duct

ivity

, W/m

K

Thermal conductivities:

Diamond is the best, 2,300 W/mKToo expensive

Copper (pure): 390 W/mK (much heavier and more expansive)

Pure aluminium: about 230 W/mK (difficult to extrude)

Extruded alloy AA6063: about 200 -215 W/mK

Cast aluminum alloys: about 120-140 W/mK

TYPICAL HEAT SINKS

COMPUTER SIMULATION

Basic study on heat sinks

Heat sink optimisation (geometry)

Customers specified simulation

Development of own rapid calculation program

Design for Manufacturability

Evaluation of cost factors

Developing the most effective heat sink solutions through the use of CFD/FEM computer simulations.

Sapa developed software for designing and optimizing air cooled

heat sinks.

TECHNICAL EXPERTISE IN THERMAL DESIGN

PROFILE DESIGN

PROFILE DESIGN

FAN CURVE AND WORKING POINT:

Fan working point: Air flow: 0.91 m3/sec (for 4 heat sinks)

Total press-drop: 670 PaAir flow per heat sink:0.23 m3/sec or 820 m3/hour

Pressure drop over heat sink: 520 Pa (670-150=520)

CFD EXAMPLE

20 W

33 W

33 W

3x20 W

4x62.5 W

COMPARISON OF TWO DESIGNS

Thermal testing setup:

LABORATORY TESTING OF COMPUTER DESIGNOver-temperature, measurement vs. calculation (SapaCool)

10,0

15,0

20,0

25,0

30,0

35,0

40,0

45,0

0 10 20 30 40

air flow, m3/hour

over

-tem

pera

ture

1.15 measure1.15 calculation

0.7 measure0.7 calculation

PROFILE DESIGNWhat is the goal?

Design the optimal profile that fulfills the demands of the application at the lowest possible cost.

To design the optimal profile, we must understand factors in production that increase costs.

Fin height to gap ratio is typically limited to 16:1

Example of 7.5:1

TOOLING COST FACTORS

Die Breakage

Alloy

Profile type and circle size

Non-fill conditionThin walls or sharp corners

Thick to Thin Ratio (variable bearings)

Tolerance requirements

PRODUCT DESIGN COST FACTORS Type of Profile

SolidSemi-HollowHollow

Fin Ratio> 6:1; >12:1

Wall Thickness Thin? Thin to Thick?

TolerancesStandard AA vs. Tighter

Cut LengthLong Lengths vs. Short Lengths

FlatnessFly-cut

FabricatingHow many directions

Surface FinishAnodize? Paint?

PROFILE CLASSIFICATIONS

SolidLow production costLow die cost

Semi-HollowTooling could break soonerHigher material and die cost

HollowHigher Material and Tooling CostMulti-Void hollows have the highest cost

CIRCLE SIZE DIAMETER

GEOMETRY OPTIMIZATION

DIFFICULT, MULTI-HOLLOW SHAPES

PROFILE DRAWING

DAMAGED DIE

EXTRUSIONS VERSUS CASTINGS

The vast majority of heat sinks are extrusions or castings

Depending on the criteria and requirements, either can work

Volume and budget are large factors in making the decision

Thermal

ConductivityLack of Porosity Near Net Shape Tooling Costs Piece Part Price

Secondary Machining Required Design

Extrusion 1 1 2 1 2 2 2-DimensionalDie Casting 3 2 1 5 1 1 3-Dimensional

Permanent Mold Casting 4 4 3 3 3 3 3-DimensionalSand Casting 5 5 4 2 5 4 3-Dimensional

1 = Best, 5 = Worst

Not all castings are the same

Do you need a three dimensional solution

Will the design change?

Can the design accept draft angles required for castings?

Is surface finish important?

EXTRUSION ALLOY VS. DIE-CAST ALLOY

TEMPERATURE: 23% REDUCTION OF MAX TEMPERATURE

Existing design (Die Cast)

Sapa’s proposed design (Extrusion)

Notice the difference in temperature only through changing the shape of the fins

THERMAL ANALYSIS OF EXTRUSION VS. CASTING

PROFILE DESIGN

WHAT IF THE RATIO IS TOO BIG TO EXTRUDE?

WHAT IF THE FINAL WIDTH IS TOO WIDE TO EXTRUDE?

HISTORYInvented and patented by the Cambridge, England based The Welding Institute (TWI) in 1991.Sapa, the largest aluminum extruder in Europe, played an active part in the process of converting theory and laboratory experiments into full scale production. In 1996, Sapa started series production in the railway and marine industries.

FRICTION STIR WELDING

DEFINITIONFSW is a method of joining two pieces of metal with no filler material by subjecting the components to heavy plastic deformation, at high temperatures, but lower than the melting point.


PROCESSA rotating tool is plunged into the components and friction heat is generated. The tool produces severe plastic deformation under high pressure, at which time the weld interfaces are stirred together and a homogenous structure is formed.


METHOD


WELD STRUCTUREFully re-crystallized fine grain micro-structure is created in the nugget by the intense plastic deformation at elevated temperature.


TIG WeldingMIG Welding


Compared to Fusion Welding, Friction Stir Welding provides:Increased strength (High tensile, fatigue & bend properties)Improved sealing, completely void-free leak proof jointsReduced thermal distortion and shrinkageImproved repeatabilityThe ability to join two different alloysSuitable for automationNo filler metal (parent metal thermal conductivity)Cost effective


MECHANICAL PROPERTIES

*MATS ERICCSSON AND ROLF SANDSTROM AT THE ROYAL INSTITUTE OF TECHNOLOGY

6082 T6 Aluminum Yield Strength (MPa) Tensile Strength (Mpa) Elongation (%)

Min specification for profile, 5mm 250 295 6

Actual Specimen 291 317 11.3

Pulsed MIG 147 221 5.2

TIG 145 219 5.4

FSW 150 245 5.7


WIDE EXTRUSIONS:7” Circle Size is the most common width of extrusions21” circle sizes are available, but expensiveWith proper design, there is no limit to the width of a FSW extrusionFSW can penetrate the surface as deep as 20 mmThe base provides an efficient thermal path to remove the heat.



This process is usually performed on FSW equipment up to thirty feet long

FRICTION STIR WELDING - CONSISTENTLY ENABLING STRONGER, MORE EFFICIENT STRUCTURES

Renewable Energy (aka Battery) Housings:Super Capacitors are being used to store energy for hybrid and electric vehicles. The capacitors are usually held together via a housing. Thermal management has been a challenge for these, however FSW extrusions are a proven solution. They provide:

Thermal Efficiency

Custom Shapes

Tight fit to capacitor

Structural integrity

Low start-up costs




Another use of FSW has been in the lighting industry where specialized lights are required to be sealed from the atmosphere. Sapa has successfully friction stir welded an aluminum extruded hollow heat sink to a casting end cap to provide a complete seal.


MOTOR HOUSINGS

BONDED FINS:Definition: Joining an aluminum extrusion or plate to a sheet of aluminum via a thermal epoxy.

Challenges: Manual operation, thermal interference


SOLUTION: Sapa FSW Module Heat SinksRatios up to 40:18% more thermally efficient than comparable bonded fin heat sinksAutomated processCustom solutions possible


FSW Bonded

FSW Heat sink vs. bonded fin heat sink:


THERMAL RESISTANCE:The thermal resistance of FSW modular heat sink is 8% lower than bonded fin design.

*THE DEFINITION OF THERMAL RESISTANCE:


LIQUID COOLINGTypical Definition: Copper pipes thermally glued to aluminum plate, than vacuum brazedChallenges: Rising price in copper, manual process, lengthy processSapa Solution: FSW cold plates with extruded “pipes”


METHODThe liquid cooler is sealed by friction stir welding the lids to the extruded body.


*PATENTED BY SAPA

EXTRUDED LIQUID COOLER*


69

METALLOGRAPHIC EXAMINATION

PRESSURE TESTThe liquid cooler can withstand burst pressure up to 90 bar.


LIQUID COOLING: COMPARISON OF TWO DESIGNS

Heat source

30

Heat source

15

199

LIQUID COOLING: TEMPERATURE & FLOWDesign No.2Design No.1

LIQUID COOLER (COLD PLATE) FOR COOLING OF ELECTRONICS IN HEV

Thermal Performance

- Alloy selection- Fin design/spacing- Heat sink orientation- Surface treatment- CFD Analysis

Extrusion Design

- Weight reduction- Profile functionality- Space limitations- Best practice mfg.

Efficient cost

effective solution

SUMMARY OF ALUMINUM EXTRUSIONS & FSW

FRICTION STIR WELDING - CONSISTENTLY ENABLING STRONGER, MORE EFFICIENT STRUCTURES

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The Advantages of Using Extrusions to Solve Thermal Management Challenges for the Automotive Industry

Stephen Jackson Business Development Mgr., TM ProductsSapa Extrusions [email protected]

Questions?

Mary GannonSenior Editor – ModeratorDesign [email protected]

mailto:[email protected]

mailto:[email protected]

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