Upload
others
View
6
Download
0
Embed Size (px)
Citation preview
18-Nov-14
Page 1
Adhesive Bonding for Aluminum Lightweight Structures
SAE Webcast November 18, 2014
Mansour MirdamadiDow Automotive Systems
Presentation Outline
18-Nov-14
Page 2
• The key drivers in use of adhesive bonding
• Challenges and consideration in selection of adhesive
• Adhesive bonding product categories
• Case studies
• Future outlook and development
Why Adhesive Bonding?
18-Nov-14
Page 3
Fuel Efficiency
CO2 Compliance
Sustainability TargetsBETAMATE™ and BETAFORCE™
Adhesive Bonding of Lightweight Materials
18-Nov-14
Page 4
• Enable use of lightweight structural materials such as aluminum, magnesium, steel, and composite systems
• Maximize the use of OEM assembly and joining capabilities
• Challenges with multi-material design– Coefficient of linear expansion – Da
– Heat/thermal capacity – D
– Residual stresses
– Component distortion due to thermal and mechanicalloads
– Impact of residual stresses on adhesion performancestrength, fatigue/durability, and corrosion
– Electrochemical potential, i.e. galvanic corrosion
– Hybrid joining
– OEM/tier part, component, sub-system assembly
Key Factors in Adhesive Selection Criteria
18-Nov-14
Page 5
• Understanding the mechanism for adhesive bonding
– Adhesion
• Mechanical interlocking
• Chemical bonding between the adhesive and the aluminum oxide or pre-treatment
• Impacted by the chemistry of the surface and the morphology
– Surface wetting characteristics
– Interface
• Adhesive bond durability
• Component assembly
Systematic Approach
Adhesive
LubricantsPre-
treatment
Influence of Coefficient of Thermal Expansion
18-Nov-14
Page 6
BETAMATE A, E = 1,700 MPa
BETAMATE B, E = 4,000 MPa
BETAMATE C, E = 2,800 MPa
Adhesive thickness: 2-3 mmSteel substrate: 0.5 mmCure: 180 °C, 30’
Adhesive thickness: 0.25 mmSteel substrate: 1.0 mmAluminum substrate: 1.0 mmCure: 180 °C, 30’
Dow Automotive Systems BETAMATE™ and BETAFORCE™
18-Nov-14
Page 7
BETAMATE Technology
1K PU
BETAFORCE Technology
BETAMATE Technology
2K PU
CDA
2K EP2K PU
BETAFORCE Technology
BETAFORCETechnology
Structural PU Structural PU
Body Shop Paint Trim Shop Repair80-160 ˚C, 30’180 ˚C, 30’ 25 ˚C
Standard to Fully Toughened
Structural Parts
1K EP
2K EP
Structural Parts
Hang-on Parts and Closures
1K – one component2K – two componentEP – epoxyPU - polyurethane
Dow Automotive Systems BETAMATE™ and BETAFORCE™
18-Nov-14
Page 8
Overview 1K EPBETAMATE
2K EPBETAMATE
1K PUBETAFORCE
2K PUBETAFORCE
E-Modulus (MPa) 100-6000 500-3000 10-300 10-300
Tensile Strength (MPa) 10-60 10-40 10-20 10-20
Tg (°C) 90-150 °C 70-110 °C - -
Impact Strength (N/mm) 10-60 8-30 - -
Thermal Stability (°C) Up to 220 °C Up to 220 °C Up to 150 °C Up to 150 °C
Typical Curing 180 °C, 30 min 2-7 d, RT60 °C, 2 h
2-10 min, 90-110 °C (full cure)
RT
Pre-curing Induction, oven, microwave
IR, Induction, oven IR, Induction, oven IR, Induction, oven
Handling strength Pre-cure 40 min - 8 h, RT Pre-cure 3-20 min, RT
Mixed-material bonding Good-excellent Good-excellent Good-excellent Good-excellent
Oil absorption Yes Some No No
Future Outlook
18-Nov-14
Page 9
• Structural applications, and load-carrying components
– Improved fatigue resistance
– Robust adhesion to aluminum alloys
– Robust adhesion for multi-material joining
– Enhanced corrosion protection under corrosive environment while under constant load
Future Outlook
18-Nov-14
Page 10
• Hang-on parts, and closure systems aluminum-to-steel bonding for body shop applications
– Focused on minimal aluminum surface distortion with long distances between mechanical fixation between aluminum to steel
No Adhesives
Development Hybrid Adhesive
1K Standard Epoxy
1k CDA
Future
18-Nov-14
Page 11
Optimized for OEM and tier assembly operations
BETAMATE™ Epoxy & BETAFORCE™ PU Technology
Hybrid Technology and New Chemistries