Donald Spinella-Joining Methods Nov21

7/26/2019 Donald Spinella-Joining Methods Nov21

1/46

Common Joining Methods Used in Aluminum Structures

D.J. SpinellaAlcoa Technical Center

November 21, 2013


2/46

Common Joining Methods Used for Aluminum Structures Agenda

IntroductionTrends in Automotive Structures

Design

Manufacturing Approaches

Automotive Joining Technology

Baseline Joining Technologies

Fusion-Based

Solid State

Mechanical

Conclusions

Questions

2


3/46

MPG

Requirem

ents

Multi-Material

High Volume Auto Body Evolution

Steel & Aluminum Hybrid(High scrap utilization, Steel to aluminum joining)

Tailoring Products

Aluminum Intensive Vehicle(Strength & ductility for safety, Robust joining)

Aluminum Closures(Increased formability for design/styling)

3


4/46

2013 Jaguar XJAluminum since 2003

2013 Jaguar XKAluminum since 2006

2013 Jaguar F Type

2013 Range Rover

Jaguar Land Rover Aluminum Vehicles

4

www.jaguarusa.com


5/46

2014 Mercedes-Benz S-Class

2014 S-Class BIW Weight (kg) 362

Front Doors (2) (Kg) 21.8

Rear Doors (2) (Kg) 21.2

Hood (Kg) 12.7

Liftgate/Decklid (Kg) 6.7

Front Fenders (Kg) 3.3

Front Bumper/Other (kg) 7

Total (kg) 434.7

Aluminum roof, doors, hood, decklid, rear packageshelf, frontend, front subframe

Saved 50 kg using aluminum over the steel body

5

Ref: 2013 Euro Car Body Conference


6/46

Automotive JoiningNorth American Industry Trends

Closures: RSW, Laser, SPR, Cl inch, Frict ion Sp ot

Structures: MIG, Adhesives, SPR, EJOT

Steel

Assembly Line

(Single / Multi)

Aluminum

Assembly Line

(Single Platform)

St / AlAssembly Line

St / Al / Hybrid

Assembly

Line

Today

Future State

All Steel

Vehicle

All Alum

Vehicle

Steel or Al

Vehicle

Steel, Al or

St/Al Hybrid

Vehicle

.

Moving to aluminum intensive vehicles

requires separate pieces of capital inaddition to assets in place for steelvehicles

Several aluminum joining technologiesnot considered as flexible to productchanges as those employed for steel

Can you proc ess mult ip le mater ials dow n the same f lowpath?

Closures: RSW, LaserStructures: RSW, Adhesives, MIG

Multiple Al

Platforms

Aluminum

Assembly Line

(Multi Platform)

6


7/46

Automotive Joining TodaySteel Sheet RSW

3k to 5k resistance spot welds pervehicle in galvanized sheet steels

Gauge Ranges

0.6 to 1.0mm (closures)

1.2 to 2.5mm (structural)

Cycle Time: 1.52.0 sec/weld to weld

Costs

Capital

Electrodes (~$0.0003/weld)

Labor, Electricity, Water Cooling

Robotic RSW is well entrenched

Extensive integrator & supply chain

AWS, ISO, JIS weld specifications Decades of data & experience

QA & NDE procedures established

Weld through lubricants & adhesives

Very flexible to product changes http://www.romaneng.com/engineering.html

http://www.romaneng.com/engineering.html

Steel RSW Section

Respot RSW Cell

7


8/46

Automotive RSW LinesFlexibility is King

Multiple automotive models flow down single respot lines. Each

gun dynamically changes its weld schedule to accommodate

the multiple stackups for each individual assembly

www.abb.com/cawp/seitp202/522132200f15d417c12577ee005a784c.aspx

Auto 1

Auto 2

Gun A

ExampleTwo different auto assemblies run down the same respot line

Stackup Range:

2.3 to 4.6mm

Force Range:

3.1 to 6.5kN

Current Range:

8 to 13kN

Gun A welds each assembly in seven locations byelectronically changing weld schedules rather than tooling

RSW process flexibility enables OEMs tomake gauge or product changes without the

downtime and capital costs to retool

8


9/46


10/46

Temperature

Pressure

Time Explosion

Ultrasonic

MagneticPulse

Cold

Friction,Upset

Al MeltingPoint

Fusion

Resistance

Soldering

Comparison of Various Joining Processes

Brazing

FSW

620 C450 C

Many welding processes dont reach the melting point of the material

Alloy of parent, heat & pressure profile, and filler metal determines Mechanical Properties (tensile, yield, elongation, fatigue)

Physical Properties (corrosion, electrical resistivity, color match

10


11/46

Competing Technologies vs. Robotic Steel RSW

Mechanical

Performance

Consumable

Cost

Flexibilityto

GaugeChang

es

GunAccessib

ility

Aluminum

to

Stee

Joining

HighStrength

Materials

Surface

Pretreatmen

ts

Adhesive

Compatible

ProcessSpee

d

Precision

Alignment

Aluminum RSW Lower Low Yes 2 Sided No Special

Practices No Yes Fast Low

Self Pierce Rivet Good Yes Limited 2 Sided Yes Special


EJOT, Flowdrill Good Yes Yes 1 Sided Yes - w/

pilot Yes No Yes Mod Mod

Mechanical Clinch Lower Yes Limited 2 Sided Yes Special


Adhesives Good Yes Yes 1 Sided Yes Yes Yes Yes Fast Mod

Blind Fastener Good Yes Yes 1 Sided Yes Yes No Yes Slow Mod

Ultrasonic Lower Low Limited 2 Sided Limited Yes No Limited Mod Mod

Friction Stir Spot Lower Low Limited 2 Sided Yes Yes No Limited Mod High

LimitedImprovement Base line Lower

11


12/46

Joining Technology Example

12

2014 GM Corvette Stingray

Resistance Spot Welding EJOTS (Flow Drill Screws) Laser Beam Welding

media.gm.com

www.technologytell.com
http://www.technologytell.com/in-car-tech/files/2013/10/BGCorvetteAssembly043.jpg


13/46

Automotive Joining TodayAluminum Sheet RSW

Aluminum sheet is spot welded in several high

volume closure applicationsStructural applications have been limited toonly a few niche vehicles

Issues versus steel RSW1. Process consistency (its all about surface)

2. Requires higher capacity welding transformers(2.5X weld current)

3. Questions on process robustness toproduction conditions (electrode angularity,gaps, etc.)

4. QA and NDE procedures are not as mature

5.Lubricant and adhesive impact on weld qualityAdvantages

Equipment designed to weld aluminum caneasily process steel

Leverages steel RSW infrastructure & logistics

Al Closure Panel Line

Aluminum Weld Section

13


14/46

Ref: AA Welding Aluminum, Table 13.1

Aluminum RSW Size, Spacing, Edge Distance & Overlap

14


15/46

Ref: AA T10, Table 7

Parameter Guidelines for RSW Aluminum Sheet

15


16/46

TSS Performance of AL Resistance Spot Welds

0.0

2.0

4.0

6.0

8.0

10.0

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

MINIMUMS

HEAR

TENSION

STRENGTH

(kN

)

THICKNESS (mm)

386 MPa and above240 MPa to 385.9 Mpa

135 MPa to 239.9 Mpa

Below 135 Mpa

Typical

AutoAlloys

AWS D17.2:2007 Aluminum Tensile Shear Strength

16


17/46

wire feed rolls

shielding gas

consumable

electrode wire

arc plasma

weld metal

base metal

Gas Metal Arc Welding - GMAW

17

www.lincolnelectric.com


18/46

Advantages

Can be used manually and automatically Suitable for welding most joint types Applicable to joining various thicknesses

(1.5 mm) and thickness combinations Lends itself to automation with mechanized

straight-tracks and robots Good travel speeds - 0.5 to1.5 m/minDisadvantages

Sensitive to variations in joint gaps andlateral positioning of the joint edges,relative to the welding torch

More prone to formation of weld porositythan GTAW

Can be used in the flat downward,horizontal, vertical, overhead andintermediate welding positions

Not as fine to control as GTAW May require parts to be cleaned of

lubricants and contaminants

GMAWAdvantages and Disadvantages

www.lincolnelectric.com

18


19/46

Vs

Laser Beam Welding - LBW

19


20/46

Laser Beam WeldingAdvantages and Disadvantages

Advantages

Higher welding speeds of travel on thin

sections

High penetration/width ratio of welds

Strong welds with UTS joint efficiency >90% insome alloys

Precise heat input which leads to narrowerweld beads, heat-affected zones and distortion

Welds Lap-Penetration and Square-Butt joints

Can maximize system utilization by switchingbetween continuous and stitch welding modes

Can be readily automated using robot or gantrysystems

Ready beam-sharing between different stationsand/or use with Hybrid welding processes(e.g., GMA/Laser) of 6xxx

Disadvantages

Certain alloys will require a filler alloy

Joint fitup and precision

Capital costs

Laser Stir Fillet Weld

Laser Beam Fillet Weld

20


21/46

Solid-State WeldingKey Characteristics

Surface oxides must be removed / displaced / dispersed so that

parent metals come into direct contact

Combinations of heat, pressure & time

Deformation may be present

Plasticized materials displace oxides, pressure allows

intimate contact resulting in metallurgical bonding

Temperatures below materials melting point

Allows dissimilar material combinations (AL to ST, AL to CU)

since intermetallics are not generated

If temperatures above melting, molten metals and

intermetallics must be expelled for good properties.

21


22/46

Butt Lap (Spot or Seam)

Cold UpsetResistance

FrictionFriction

StirMagnetic

PulseUltrasonic Explosion

Area


23/46

Ultrasonic Welding Process

Anvil

Sonotrode TipVibrates @High Freq

Force

Force

Wedge-ReedLateral Drive

Sonotrode

Transducer

Transducer

WedgeReed

23

Hetrick et al., Ultrasonic Spot Welding, A New Tool for

Aluminum Joining, AWS Welding Journal, Vol 84, Feb 2005.


24/46

Advantages

Low # Process Inputs

Low heat distortion

Low heat-affected zone

Weld through lubricants

Surface preparation not criticalExcellent electrical joint properties

Low energy joining process

No arcs & fume emissions (clean)

2 to 3 second cycle timesBimetallic combinations

No water cooling or filler materials

Disadvantages

Thickness limited to approx. < 3mm

Difficult for deep parts (throat depth)

Requires good workpiece alignment

Applications

Electrical Wiring

Light gauge sheet joining

Sheet to wire joints

Bimetallic, multi-material joining

Products in consumer, industrial,

auto, defense, and aero

Ultrasonic WeldingAdvantages and Disadvantages

24


25/46

Ultrasonic Process Variables and Mechanical Performance

Major Process Variables

Vibration Amplitude (Microns), Force (Pressure), Time,Tool Geometry

Weld Energy = Power * Time = (Amplitude * Force ) * Time

Increased Power or Time necessary with partcontamination or tool wear

Hetrick et al., Ultrasonic Spot Welding, A New Tool for Aluminum Joining, AWS Welding Journal, Vol 84, Feb 2005.

25


26/46

Advantages

Good mechanical properties Minimal weld induced distortion

Full or partial penetration from one side

Square butt & lap-penetration type joints

High quality welds involving fewer repairs

and rejects No filler alloy addition & shielding gas

Very simple to operate and maintain

Welds aluminum alloys normally considerednon-fusion weldable (e.g., 7050, 7075)

Disadvantages

Requires good fitup and clamping systems

Friction Stir Welding Process

26


27/46

Lap-Fillet

Lap-

Penetration

Square-Butt

Square-

Butt

Lap-

PenetrationLap-Fillet

Part A

Part B

Ideal for FSW Challenging Highly specialized

FSW Joint Types

27

Advancing SideRetreating Side


28/46

4540

35

30

2520

15

10

5

0

Tensile Strength Yield Strength % Elongation

Mechanical Property

S

trength(ksi)orelongation(%)

Base Metal

Friction Stir Weld

GMA Weld

FSW versus GMAW Property Comparison: 6061-T6

28


29/46

Friction Stir Spot Welding

Advantages

Replaces RSW and mechanicalfastening joints

Minimal weld induced distortion

Stitch and refill variants

Low consumable & infrastructure

costs (low electricity, no chillingwater)

Welds aluminum alloys normallyconsidered non-fusion weldable(e.g., 7050, 7075)

Disadvantages

Cycle time for thick stackups

Switching between different stackupsand material combinations

www.kawasakirobotics.com

Arul et. al., Effects of Surface Treatment (Lubricant)on Spot Friction Welded Joints Made of 6111-T4Aluminum Sheets, SAE Paper 2007-01-1706

29


30/46

Friction Spot Welding Fatigue Performance0.94mm 6111-T4

30

Lin et.al., Failure modes and fatigue life estimations of spot friction welds in lap -shear specimens of aluminum6111-T4. Part 2: Welds made by a flat tool, International Journal of Fatigue, Vol. 30 (2008) 90 -105

Alcoa RSW FatigueData on 1mm Al

Auto Alloys


31/46

Friction Welding Process - Direct Drive

Position, Clamp, &rotate parts

Advance non-rotary part,

start pressure

Heating

Forge / Upset

Force pushingparts, increasingfrictional heat

Flash-off

High forgingforce applied

Rotation and forceapplied for aspecific period

Single part rotatesto desired speed

31


32/46

Advantages

Low Number Process Inputs

Low heat distortion

Good joint properties (low heat-affectedzone)

Weld through lubricants

Surface preparation not critical

Excellent joint properties

Low energy joining process

Clean process - no arcs and fume

emissionsFast second cycle times

Bimetallic combinations

No water cooling or filler materialsrequired

Disadvantages

Equipment may be capitallyintensive

Requires good workpiece alignment

ApplicationsAutomotive driveshafts

Suspension rods, axles

Bimetallic joining

Products in Auto, Defense, Aero

Friction WeldingAdvantages & Disadvantages

32


33/46

Mechanical Fastening: SPRSelf-Piercing Rivet

Factors for SPR Joint Design

Total Stack-Up Thickness

Determines rivet length

Flange or Overlap Width

Edge Distance

Tool Clearance

Materials being Joined

Aluminum

Steel

Multi-Materials (Hybrids)

Stack-up / Orientation

Softer (top) to Harder (bottom)

Thick to thin, thin should be no less than1/3t of the thicker

Rivet Diameter

3 mm or 5 mm

Joint strength Robustness of joint

Access

Rivet Length

3 mm rivet, 1.5 - 3.0 mm > than stack

5 mm rivet, 2.0 - 4.0 mm > than stack

33


34/46

Mechanical Fastening: SPRSelf-Piercing Rivet

6000

5000

4000

3000

2000

1000

03 mm 5 mm 3 mm 5 mm

1 mm to 1.5 mm

Material

1.5 mm to 1.5 mm

Material

6111-T4 Alloy

Rivet Diameter

34

LapShearTensileS

trength,

N,


35/46

Mechanical Fastening: EJOT Flow Drill Screws

Weber Screw Driving Systems

1. FLOW DRILLING SCREW (FDS) is applied to surface with medium thrust andspindle rotation.

2. As friction and heat increases, the surface plasticizes and begins to flow.3. Material begins to form the extended threading are behind the application.4. As the flow phase ends the thread rolling phase begins with lower RPM on the

spindle.5. The screw now begins to act like a normal fastener and is driven to a torque.6. The fastener is seated as it would be in any normal toque strategy. As the

materials cool it also contacts around the threads for added joint integrity.

35


36/46

Mechanical Fastening: TOX Mechanical Clinch

TOX Clinching Process

Material Stack-up / OrientationPreferable to have thicker or harder material on punch sideMinimum single sheet thickness of 0.3 mm (depend on TOX diameter)Maximum combine thickness is 8 mm (depend on TOX diameter)

Total stack-up of 2 to 4 layers possible

TOX diametersAvailable in 3, 4, 5, 6, 8, 10, and 12 mm button diameters

36


37/46

Mechanical Fastening: TOX Mechanical Clinch

0

50

100

150

200

250

300

350

400

450

500

lbs

Force

6 mm 8 mm

Button Diameter

Effect of Button Diameter

1mm : 1mm 6111-T4 Joints

Pull Strength

Shear Strength

0

50

100

150

200

250

300

350

400

450

500

lbs.

force

1mm:1mm 6111-T4 1mm: 2mm 5754-0

Alloy / Gauge Combination

Effect of Alloy

with 8 mm TOX

Pull Strength

Shear Strength

TOX Joint Strength

37


38/46

Aluminum Automotive Joining Applications

38


39/46

Aluminum Now, Aluminum Association, January/February 2003 6061 Extrusions

Friction Stir Welded Suspension Link for Lincoln Town Car

39

www.aluminum.org


40/46

Aluminum Now, Aluminum Association,

November/December 2002

Pretreated aluminum sheet 40% lighter, 60% stiffer than previous

steel-body XJ

Stamped sheet panels assembledwith adhesive bonding incombination with self-pierce

riveting

Jaguar XJ

40


41/46

Aluminum Now, Aluminum Association,

November/December 2001

30 meters of laser welds

http://www.autoaluminum.org/

Aluminum Associations Aluminum Welding Seminar, 2003

Audi A2

41

A i Cl P l RSW A li i


42/46

General Motors YukonAL liftgate

DaimlerChrysler Pacifica

AL hood


www.chrysler.com


Automotive Closure Panel RSW Applications

Nissan Altima

AL hood and decklid

42

Ford Explorer

AL hood and fenders

Acura MDX

AL hoodwww.acura.com

www.ford.com

www.nissanusa.com

www.gm.com

A t ti Cl P l M h i l F t


43/46

Chrysler Concord

AL hood (SPR, TOX)

GM U-Van (Venture)AL hood (TOX)

Plymouth ProwlerSPR body and panels

Automotive Closure Panel Mechanical Fastener

43

www.gm.com

www.chrysler.com

www.chrysler.com


44/46

A k l d t


45/46

Acknowledgements

The presenter would like to thank the following individuals for supplyinginformation and slides for this presentation: Dan Bergstrom, Russ Long,Israel Stol, and Kyle Williams.

45


46/46

Date post:	02-Mar-2018
Category:	Documents
Upload:	foisal-ahmed-mirza
View:	220 times
Download:	0 times

Donald Spinella-Joining Methods Nov21

Documents