joining technologies in automotive industry

Joining technologies in automotive industry

Some examples of Body In White

joining methods

© Valmet Automotive

Overview Used Joining Technologies in the Automotive field (BiW)

3/7/2016 2 Timo Karhu

Welding

Gluing

Sheetmetal Screwing

Riveting

Clinching

Hybrids


Welding Most common welding processes in Automotive BiW


Resistance Welding Laser Welding Arc Welding

Spot Welding MIG / MAG

CMT

TIG

Laser Welding

Electron Beam Welding

Remote / Scanner Deltaspot

Projection Welding

Stud Welding

Laserhybrid

Hardfacing

Used by VA higher tolerances due to self clamping

Partly used by VA

Seam Welding

Usable for Aluminium

moderate tolerances due to gap filling

Requires small tolerances, expensive clamping

Laser Weldinggun


Welding – Resistance Welding Aluminium Spot Welding - Deltaspot (Fronius)

• Concept

- Influencing the resistance of the material

by adding a driven metal strip. The strip is

”endless” and is driven after every new

spot welded.

• Advantages

- No aloycreation of welding material on the

welding caps

- Can influence the position of the welding

lense and shape, when different material

strenghts and difficult workpiece

geometries are used

- Endless metal strip, has not to be changed

during production time (except 3-Shift)

- Can influence parameters positively

• Disadvantages

- Higher Invest compared to standart SW

tooling

- Changing Metal Strip more complicated


Deltaspot

Welding Gun

3-Sheetmetal junction of AlMg3 with 17kA, 700ms, 4kN

(0.3mm,1.0mm & 2.0mm)


Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec)

• Concept

- Multi-ring domed electrodes

- CSS weld schedules

- Aluminum specific equipment set

• Advantages

- Almost normal type of welding equipments

can be used

- Allow different material strenghts and smal

workpiece geometry variation.

- ”Standardized” type of process

• Disadvantages

- Higher Invest compared to standart SW

tooling

- Needs automated electrode cap dressing

and electode cap changer

- Higher weight of welding gun



Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec)

• Concept




• Multi-Ring Domed Electrodes

- Standard weld cap dressed with custom

cutting blade

- Multi-Ring texture strains the part surface

to reduce contact resistance

- Domed cap improves robustness to non-

idel welding conditions (i.e. off angle, gaps

between parts)



Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec) Cont.

• Concept




• CSS Weld Schedules

- Conditioning

• Remove effects of part variance

• Seats caps without melting

- Shaping

• Weld nugget initiation at center of

welding location

- Sising

• Nugget growth at lower current levels

• Improve heat affected zone



Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec) Cont.

• Concept




• Equipment Set

- MFDC weld control

• 1200 Amp WTC

- Larger weld transformers

• Weld current to 55 kAmps

- Increased gun stiffness

• Weld forces to 5.4 kN

- Automatic tip dressing

• 40 - 80 welds/dress

- Automatic cap changing

• 30 – 60 dresses/cap



Welding – Resistance Welding Projection Welding

• Concept

- Influencing the resistance of the material

by chaniging geometry.

• Advantages

- Can reach corners and other difficult

geometries through adaption of welding

geometry

- Can influence welding parameters

- Low waste on welding caps

- Multiple weldings at once

- Creation of mixted microstructure possible

- Different material strenghts prossible

• Disadvantages

- Additional process needed (forming

geometry)

- Needs special equipment = higher invest

compared to standart SP 3/7/2016 9 Timo Karhu

Melted material

circulates with ca.

20m/s in the

magentic field

Projection


Welding – Resistance Welding Seam Welding

• Concept

- Continous resistance welding through

replacing electrodes with copper wheels.

• Advantages

- Continous seams, saving gluing process

- Easy to paint

- Good optical aperience

- Can create spots and continous seams

• Disadvantages

- Aloy creation on the wheels, when using

Aluminium or zinkplated materials

- No easy reaplacement of wheels possible

- Complex process, hard to stabilze

- More sensors needed trough moving

along a defined path

- no small curves possible 3/7/2016 10 Timo Karhu

Seam on a tube


Welding – Arc Welding TIG Welding (Tungsten Inert Gas)

• Concept

- Creates an arc between non consumable

tungsten electrode and work piece.

Ignition through short circuit or high

frequency voltage.

• Advantages

- Very good optical seams

- Good control of process

- Mainly used for non ferro metals

(Aluminium, Stainless Steel, Copper,

Magnesium)

- Requires accessabilty only from one side

• Disadvantages

- Very slow compared to other arc welding

processes

- Requires skilled labour

- Not easy to automate with e.g. Industrial

robots 3/7/2016 11 Timo Karhu


Welding – Laser Welding Standard Laser Welding / Soldering

• Concept

- Focussed laser photones heat up the workpiece

and, if used, suplementary material.

• Advantages

- Very fast welding speed (>4,5m/min)

- Same Hardware used for welding and brazing

- Good looking seams

- Top hat optics get energy density more

homogenious

- Workpiece only heats up at the seam

- No strong deformation of workpiece


• Disadvantages

- Very high invest, operational costs & maintenance

- Requires high precision from workpiece and

environment

- High effort for safety (Lasercabins, glasses)

- Reflective material needs very high energy


Laser brazing of rear door (Audi A3)

Laser welding


Welding – Laser Welding Laser Soldering – Valmet (Scansonic)

• System description

- Power source Trumpf TruDisk 4002

- Welding optics Scansonic ALO3

- Wire feeding Binzel

- Welding wire Fontargen A202 M EC 1,0

mm (CuSi3Mn)



Welding – LaserWelding Laser Soldering – Valmet (Scansonic)



Welding – Laser Welding Remote / Scanner Welding (Laser)

• Concept

- Laserbeam is positioned with fast mirriors to the workpiece.

• Advantages

- Very fast positioning and welding speed

- Small seams possible (<0.5mm)

- Also used for lasercutting

- Can be used for gap filling by rotation circles / ellipses

- High distance from workpiece

- Can reach difficult areas




• Disadvantages

- Very high invest, operational costs & maintenance

- Requires high precision from workpiece and environment

- High effort for safety (Lasercabins, glasses) 3/7/2016 15 Timo Karhu

Remote welding door

Up to 200 welds / minute


Welding – Laser Welding Laser Scanner Welding – Valmet (RobScan)

• System description

- Power source, Trumpf TruDisk 4002

- Welding optics, Trumph PFO

- ”Welding on the fly” - operation

- Machine vision for quality inspection,

Hema electronics GmbH VISIR (Daimler

patented)

• Robscan Weld Seam Characteristic

- Robscan welds consists of 4 operations

per seam

• Dimpling (1)

• Deep penetration welding (2)

• Reheating of the seam for heat

conduction measurement

• Final Heat conduction welding (3)


Deep penetration weld (2)

Heat conduction weld (3)

Dimple (1)

Vaporization

channel

Metal Sheet




Dimples

Welding finished


Welding – Hybrid Welding Laserwelding Gun (IPG Photon)

• Concept

- Combination of concept advantages of spotwelding

with laser technology.

• Advantages

- Very fast positioning and welding speed (80mm/s)

- Speed andvantage over spot welding up to 50%

- Small seams possible (<0.5mm)



- No high requirement in accuracy of workpiece

- No Lasercabin needed

- Can be used on Aluminium

• Disadvantages

- Requires accessabilty from both sides

- Combination with glue is questionable

- high invest, operational costs & maintenance

- Needs flat workpiece geometry


Classical SW 10,5 sec

Laserweldinggun 5,0 sec


Gluing General Gluing information

• Concept

• Advantages

- Nearly all kind of materials can be

combined

- Big areas are easier to cover than with

other joining technologies

- Good damping properties

- Lightweight

- No microstructure damage of material

- Sealing

- ”Cold” connection – needs usually curing

• Disadvantages

- Preparation processes needed

- Not as resistend towards temperature

- Aging

- Not testable (destructionfree) 3/7/2016 20 Timo Karhu


Gluing Application in BIW

3/7/2016 21



3/7/2016 22



3/7/2016 23


Screwing – Sheetmetal screws FDS – Flow Drill Screw

• Concept

- The friction heat, generated through

high force (600-2000N) and turn

speeds (2000-6000rpm), melts a

hole. After reduction of the rpms a

will then form a screw thread which

is thicker than the original material

• Advantages

- Thicker screw thread than with

normal sheet metal screws

- No chipping

- Fast process

- Accessabilty only from one side

- Can be loosend afterwards

• Disadvantages

- Screw can be tightend again

- can’t be used on visible surfaces 3/7/2016 24 Timo Karhu


Riveting Piercing & Non Piercing

• Concept

- Riveting using friction and clamping forces

to connect workpieces. Piercing rivets are

used mainly in sheetmetal production as

BiW

• Advantages

- Can combine nearly any material

combinations

- High forces through frictional and clamping

connection

- Cold connection

- Can be easily combined with glue

• Disadvantages

- Slow process compared to welding

- Requires accessibility from both sides

- Contact corrosion between rivet and

material possible 3/7/2016 25 Timo Karhu

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Piercing Riveting


Clinching Point form / Flat form

• Concept

- Assembly parts from sheet metal and

formable materials are stacked in the

joining position and fixed. A press ram into

the die and deformes the parts plastically.

• Advantages

- Cool joining technology

- No special treadment of the parts before

or after

- Better surface than rivets

- One side easy to paint

• Disadvantages

- Requires accessabilty from both sides

- Slower than spot welding

- Contact corrosion possible



Hybrid – Clinchriveting Fraunhofer IWU & TOX (Tox patented)

• Concept

- Using a rivet as a stamp for clinching,

which remains in the connection. The used

rivets are piercing or hollow punch rivets

without penetrating the workpieces

• Advantages

- Higher resistance of the connection

- Better combination with glue (no airgaps)

- Better surface quality (no hole)

• Disadvantages

- More complex

- Slow process


TOX Clinchriveting

Center Deep

drawing

Flow Rivet de-

.formation

IWU Clinchriveting

Anvil replaces the matrix


Hybrid – Aluminium Weldbrazing In Development - patented by VW

• Concept

- Joining Aluminium and form hardned

steel (22MnB5) with a spotwelding

method. Creating CMT suplementary

material depots on the steel before to

perform a welding and brazing process

at once.

• Advantages

- Combination of most important actual

materials in BiW through a fast and well

known process

- Nearly no change in production

equipment

- Can be combined with gluing

• Disadvantages

- Addittional processes needed to create

solder depots

- Aluminium alloys to welding gun

electrodes and needs more ”cleaning”

(polishing, milling, scraping)


22MnB5

AlMg3

Depot

Spotwelding

electrodes

Weakest spot = AlMg3 Structure

Soldered / brazed

connection

Welded

connection


Hybrid – Rivet Welding In Development - patented by VW

• Concept

- Spotwelding a rivet like metal pin to the

carrier material and clamping the inner

surface material

• Advantages

- Combination of different materials

- Ideal for composite and lightweight design

- Very good surface on the carrier material

- Can be combined with glueing

• Disadvantages

- Addittional processes needed for holes

- Addtional parts needed (rivets)

- Contact corrision not solved

- Needs accessabilty from 2 sides


Carrier

material

Inner

surface

Rivet

Spotwelding

electrodes

Rivet

joining technologies in automotive industry

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