scale and complexity for vehicles joining by plastic...

STC F Keynote 2013

Joining by plastic deformationCold welding, friction stir welding, self-pierce riveting,

mechanical clinching, joining by forming, etc.

CIRP office: 9 rue Mayran, 75009 PARIS – France, E mail: [email protected], http://www.cirp.net

International Academy for Production Engineering63rd General Assembly - Copenhagen - Denmark, August 18-24, 2013

by

K. Mori, N. Bay, L. Fratini, F. Micari and A.E. Tekkaya

Presenting author: K. Mori, Frontier Forming System Laboratory, Department of Mechanical Engineering, Toyohashi University of Technology, Japan. Email: [email protected]

CIRP Annals - Manufacturing TechnologyVolume 62, Issue 2, 2013, Pages 25-28 (in press)

2

Joining by plastic deformation

1. Motivation2. Cold welding3. Friction stir welding4. Self-pierce riveting and mechanical

clinching of sheets5. Joining by forming6. Future trends

3

10,000 - 30,000 parts Several

million parts

Parts in vehicles

Scale and complexity for vehicles

Joining of parts

4

Typical joining processes

Welding: thermal effectsAdhesive bonding, mechanical

fastening: low strengthHigh performance, high productivity, low cost, dissimilar materials

Arc welding

Resistance welding

Laser welding

5

Forming processes using plastic deformation Rolling

Sheet metal forming

Drawing

Extrusion

Forging

Sheet metal forming

Shaping

Forging

Use of plastic deformation for joining

6

Joining processes by plastic deformation

Metallurgical joining (bonding):Cold welding by rolling, extrusion, forging, etc.Friction welding, Friction stir weldingResistance welding, etc.

Mechanical joining:Self-pierce rivetingMechanical clinchingJoining by forming such as hydroforming,

electromagnetic forming, incremental forming, etc.Fastening such as hemming, seaming, staking, etc.

7

Joining mechanismMetallurgical joining: large

plastic deformation

Holder

Punch

Upper sheet

Die

Interlock ∆x

Lower sheet

Mechanical joining: control of plastic deformation

The oxide films and contaminant layers at the interface between workpieces are broken up by severe plastic deformation, and the resulting clean surfaces are bonded by high pressure.

The workpieces are mechanically interlocked by plastic deformation.

Severe plastic deformation

High pressure

8

Advantages and disadvantages of joining by plastic deformation

Advantages Disadvantages Wide range of joining

materials, including dissimilarones (metallic/non-metallic)

No distortion, embrittlementor residual stresses due tomissing microstructuraltransformation

High process reliability andsimple quality control

Environmental safety

Mainly overlap joint Geometrical unevenness

of joining zone due tonature of processes

More difficult correctionand repair

Lack of standardisationand calculation methods

9

Conventional joining processesby plastic deformation

Recent developments and progress of joining processes by plastic deformation

Seaming for beverage cans

Riveting

Friction welding LidCan body

Double seaming

10




11

Cold welding process

• Surface preparation: scratch brushing (within 10 minutes), electrochemical treatment and chemical plating

• Plastic deformation: to create clean interface

• Pressure: to establish welds

Soft: large deformationHard: small deformation

Roll

Roll bondingsolid-state welding process

12

Cold welding processes

Roll

Roll

Base metal Cladding metal

Roll bonding AlZn-Fe bearing

Shear welding

Butt welding

Martinrea Honsel

BWE Ltd.

Wire ends, busbars, wheel rims

Air cooler

13

Joining mechanism of cold welding(a)

(b)

(c)

(a) Brittle cover layers created by scratch brushing (20 m), and contaminant films of oxides and water vapour (10-100 nm)

Scratch brushed surface

(b) Fracture of cover layers and contaminant films by larger surface expansion

(c) Extrusion of virgin metal and bonding

100μm

200μm

50μm

5μm

Bay 14

Calculation of bond strength

000 '1

'1

p

YYYpp EB

Extruded virgin metal Film layer

Bay

Total reduction in thickness r = (h0-h1)/h0

Bon

d st

reng

th

B[M

Pa]

Al-Al

σB: bond strengthσ0: flow stress of material after

deformationp: normal pressure on base metal

surfacespE: pressure required to extrude

through cracks of cover layerY´: threshold surface exposure for

film layer = ψf2

ψf : fraction of film layer on scratch brushed surface

15

Cold welding of dissimilar metals

Bon

d st

reng

th [M

Pa]

Total reduction in thickness r = (h0-h1)/h0

Successful weldingcombinations

Ti CdBe Pd Pt Sn Pb W Zn Fe Ni AuAgCu AlAlCuAgAuNiFeZnWPbSnPtPdBeCdTi Wodara

Milner et al.

16




17

Friction stir weldingLarge plastic deformation:

heat generation and metal stirring

Tool

Pin

Tilt angle

SeamFeed rate

Rotational speed

A.S.R.S.

Feed rateRotational speed

AA6181-T4 DP600Material: aluminium alloy, magnesium, copper, steel, stainless steel, dissimilar materials

18

Application of friction stir welding

Rocket

Automobile

Ship

FSW

Train

Airplane

19

Friction stir welding processesHeat generationMetal flowSeam

R.S. R.S.A.S. A.S.(a) Butt joining (b) Lap joining

R.S. A.S.

(c) T-joining (d) Friction stir spot welding

AluminiumSteel

Mazda Motor

20

Properties of joined workpieces

Base metal TMAZ Nugget HAZ

Welding lineA.S. R.S.

1 mm

(a) Microstructure in cross section (b) Joined aluminium alloyof AA7075-T6 butt joint sheets

FSW

MIG welding

Fratini Hitachi, Ltd

21

Strength of joint

AZ31

Ti64

AISI430

AA1050-H24

AA5083AA7050

A319

AA6061-T6

AA7039

5060708090

100110120130

0 2 4 6 8 10Rat

io o

f ten

sile

stre

ngth

of

join

t to

base

mat

eria

l[%

]

Thickness [mm] Number of cycles to fracture1.0E+05 1.0E+06 1.0E+07

120

100

80

60

40

FSWTIG

MIG

Stre

ss a

mpl

itude

[MP

a]

(a) Static strength (b) Fatigue strength

Ericsson

Small residual stress

22

Joining of dissimilar metalsAA6181-T4 – DP600

Stainless steel – AA6013

CuDHP – AA5083Magnesium alloy – AA6061

A.S.R.S.

AA6181-T4 DP600

A.S. R.S.

3 mm

AA2024-T4 skin and AA7075-T6 stringer

23

Finite element simulation of temperature distribution in friction stir welding

FratiniMaterial constants: temperature dependent

Butt joining Lap joining

24




25

Self-pierce riveting for joining sheets

Die

Holder

Rivet (hard steel)

Punch

No pre-drilling hole Short joining time

Hydraulic unit

C-frameSheet: aluminium alloy, steel, copper, magnesium, sandwich materials, plastics, multiple sheets, dissimilar materials

Automobile

26

Self-pierce riveting for joining sheets

(a) Start (b) Driving through (c) Formation of upper sheet interlock

Die

Upper sheet

Punch

Sheet holder

Flaring

InterlockRivet

Lower sheet

Requirements for successful self-pierce riveting • Driving of rivet skirt through upper sheet• Flaring of rivet skirt in lower sheet• Avoiding of fracture in lower sheet

27

New self-pierce riveting processesHydro-self-pierce riveting: Neugebauer

Joining of multiple sheets: Abe

Aluminium alloy rivet: Abe

High speed self-pierce riveting: Wang

28

Mechanical clinching for joining sheets

Requirements for successful mechanical clinching• Forming of interlock• Avoidance of excessive thinning of upper sheet at neck of joint• Avoidance of fracture of sheets

ダイ

(a) Start (b) Bulging (c) Compression (d) Formation of interlock

Sheet holder

Upper sheetLower sheet

Die

Punch InterlockNo rivet

29

Application of mechanical clinchingAutomobile Electrical appliances

Sheet: steel, aluminium alloy, coated, copper, magnesium, dissimilar materials

ToxPressotechnik

30

New mechanical clinching processesDieless clinching of magnesium: Neugebauer

Clinching with prepunched sheet: Merklein

Two-stage flat clinching: Tox

0

20

40

60

Rat

io o

f cor

rosi

on

resi

stan

ce [%

]

Depression Projection

Spot welding

Rust

Rust

Zinc-coated steel sheets: Abe

Heated die

31

Static and fatigue strengths in tension-shearing test of aluminium sheets joined by self-pierce riveting, mechanical clinching and resistance spot welding

(a) Static strength (b) Fatigue strength

Load

[kN

]

Stroke [mm]

Self-pierce riveting Resistance spot welding Mechanical clinching

0

1

2

3

4

5

6

1 2 3 4 5Mori

Mechanical clinching

Resistance spot weldingSelf-pierce riveting

1

2

3

103 104 105 106 107Number of cycles

Load

am

plitu

de [k

N]

(a) Mechanical clinching (b) Self-pierce rivetingWeld nugget

(c) Resistance spot welding

Complete bonding

Slight slip

32

Joining of high strength steel and aluminium alloy sheets

SPFC980, 1.4 mm

A5052,1.5 mm

Conventional die

Tensile strength of lower sheet [MPa]

0.25

1000800600400200

0.20

0.15

0.10

0.05

0

Inte

rlock

[mm

]

Conventional

Optimised

Cracks

Optimised die(a) Self-pierce riveting (b) Mechanical clinching

Mori

33

Finite element simulation of self-pierce riveting and mechanical clinching processes

Mori

RemeshingDriving through upper sheet

Self-pierce riveting

Mechanical clinching

34




35

Mechanism of joining by forming

(a) Interference-fit joint

(b) Form-fit joint

Ring

Tube pf

pa

Positioning Maximum expansion under Elastic recoveryforming pressure

Joining processes by electromagnetic forming, crimping, shear spinning and rolling are similar mechanism.

Elastic

Plastic

Hydroforming

36

Application of joining by forming(e) Torque tubes (PST Products GmbH)

(c)

Electro-magnetically crimped joints

Joining byhydroforming

Joint by electro-magnetic forming

Magnetic impulse welded

joint

Electromagnetically crimped joint

(a) Camshaft: joining by hydroforming

(b) Heat exchanger: joining by rolling or hydroforming

Tube-to-tubesheet

joint

(c) Mechanically crimped water hose coupling (NEOPERL GmbH)

Joining probe

(d) Lightweight frame structure (SFB Transregio 10)

(f) Hydraulic compensation vessels (Poynting GmbH)

CT-scan of joint

37

Current

LiRiC

I(t)

Current Tool coilMandrel

Tube Tube Collar

p(t) p(t)8.0

6.0

4.0

2.0

Join

t stre

ngth

[kN

]

0 0.4 0.8 1.2 1.6 2.0 2.4Gap a0 [mm]

Tensile strength of tubeSteel 9SMn28k

AlMgSiAlCu4PbMg

13.5a0 Magnetic field: repulsive force

Tekkaya, Kleiner

Joining by electromagnetic forming and magnetic impulse welding

Induced current Magnetic fieldWeld seamTarget plate

LiRiC

I(t)

Flyer plate

(a) Compression (b) Expansion

38

Joining by crimping, shear spinning and rolling

(a) Mechanical crimpingCrimping die

Fitting Hose

Sleeve

Inner partner

Tube

Elastomer(b) Hydraulic crimpingAltan

Mandrel (2 parts) Ring

Roller

(c) Produced cartridge with ring magnets

Groche

(a) Preforming (b) Final cycle

(a) Adjustable joining zone (b) Adjustable expansionCollar

Cage

Cone

TubeRolling element

Tapered mandrelTube

Collar

Hagedorn

Segmented tools

Rubber

39

Manufacturing of shaft having flange

Cooling

Clamping

Punching

Non-heated bar

ScrapHeated disk

Interfacial pressure

Disk having bars

Pipe having flange

Matsumoto

(a) Forming of teeth (b) Joining of by extrusion shaft and disk

Die

Shaft

Disc

Work-hardened teeth

(c) Product Kitamura(a) 1st wrinkling (b) 2nd wrinkling (c) Product

Tube Ring

Martins

40




41

Joining of materials having low ductilityand high strength

Magnesium alloy sheets: laser assisted self-pierce riveting

Ultra-high strength steel sheet: mechanical clinching

Facture

Optimisation of tool shapes in mechanical clinching

980 MPa sheet

Abe

Durandet

Sufficient ductility

42

Friction stir welding of of titanium alloy workpieces

HAZStirred zone

A.S. R.S.

Broken pin

Fratini(a), (b) Tool steels (c) Tungsten

carbides

Polycrystalline cubic boron nitride (PCBN), iridium-based tool

Ti–6Al–4V titanium alloy sheets

43

Integration of joining into other manufacturing processes

Cutting

Joined products

Bar

SheetStamping + joining

BarForging + joining

Joining by forming,hemming, staking, mechanical clinching, self-pierce riveting

Reductions in production cost and lead time, improvement in dimensional accuracy

44

Application of CFRP

Aluminium profiles

CRFP primary structure

Bicycle: TU Dresden

Airplane: AirbusAutomobile: BMW

GFRP ring and aluminium tube:Joining by hydroforming

45

In-process heat treatment using friction stir welding and laser impact welding

74

7780

83

86

89

92

Without cooling

Water cooling

Rotational 715 715 1500speed [rpm] Feed rate 214 105 105[mm/min]

Rat

io o

f ten

sile

stre

ngth

of

join

t to

base

mat

eria

l[%

]

Fratini

Water

Hold down

Target block

Flyer plateSubstrate Laser pulse

Jet

Darkened surface

400 μm

stainless steel (100 µm)

Vollertsen

46

Joining processes by plastic deformation

Roll

Roll

Base metal

Cold welding Friction stir welding

Self-pierce riveting Mechanical clinching

Joining by forming

47

Acknowledgements

J.M. Allwood, T. Altan, A. Azushima,P.F. Bariani, L. Filice, P. Groche,M.K. Khraisheh, J.G. Lenard, M. Liewald, P.A.F. Martins, M. Merklein, R. Neugebauer, S.I. Oh, K. Osakada, F. Vollertsen, J. Yanagimoto, Y. Abe, C. Weddeling

48

Thank you very much

scale and complexity for vehicles joining by plastic...

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