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
Joining by plastic deformation
1. Motivation2. Cold welding3. Friction stir welding4. Self-pierce riveting and mechanical
clinching of sheets5. Joining by forming6. Future trends
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
Joining by plastic deformation
1. Motivation2. Cold welding3. Friction stir welding4. Self-pierce riveting and mechanical
clinching of sheets5. Joining by forming6. Future trends
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
Joining by plastic deformation
1. Motivation2. Cold welding3. Friction stir welding4. Self-pierce riveting and mechanical
clinching of sheets5. Joining by forming6. Future trends
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
Joining by plastic deformation
1. Motivation2. Cold welding3. Friction stir welding4. Self-pierce riveting and mechanical
clinching of sheets5. Joining by forming6. Future trends
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
Joining by plastic deformation
1. Motivation2. Cold welding3. Friction stir welding4. Self-pierce riveting and mechanical
clinching of sheets5. Joining by forming6. Future trends
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