Improve Bond Durability of Structural Adhesives for Lightweight Materials. Syed Mahdi Scientific Principal Henkel Corporation September 12, 2018

Transcription

1 Improve Bond Durability of Structural Adhesives for Lightweight Materials Syed Mahdi Scientific Principal Henkel Corporation September 12, 2018

2 Automotive Industry: Improvements in crash worthiness Source: NCAP 2

3 Automotive Target: CO 2 Emissions Reduction Lightweight is a strategic Henkel Innovation Target 30% emissions reduction by 2020 Move to lighter materials USA Car EU Japan China 50% 50% 30% 30% 20% 20% 10% 10% Potential Weight Savings Potential Weight Savings Aluminum Steel-Alu- Aluminum Steel-Alu- Hybrid Innovative Hybrid Innovative Steels Steels Composites Composites Year Year Source: ICCT We develop technology to drive adoption of lightweight materials & increase safety 3

4 Agenda 1. Substrate Technology & Bonding 2. New Structural Adhesive Solutions 3. Mix Materials Bonding 4. Q & A 4

5 Materials in BIW: Usage Projection Material Distribution in the U.S. Fleet (Body-in-White Plus Closures), 2010 to % 5% 5% 15% 15% 12% 16% 10% 5% 15% Mild Steel HSLA High Strength Low Alloy HSS High Strength Steel AHSS Advance High Strength Steel UHSS Ultra High Strength Steel Boron/Martensite AL 5000/6000 Aluminum 5000/6000 Aluminium/High Strength % 25% 10% 5% 4% 1% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Source: CAR Research Mg Magnesium CFRP/Comp. Carbon Fiber Reinforced Plastic/Composites 5

6 The right material, at the right place Material distribution in BIW Aluminum penetration rates for closures Deep Drawn Steel 19% 180 MPa 7% MPa 9% 260 MPa 10% Hoods Doors Others 5% AlSi Aluminum 2% 1000 MPa 12% MPa 1% MPa 14% MPa 21% Liftgates / Trunks Fenders 6

7 Challenge Lightweight Design Material Process Engineering 1 Material 1 adhesive profile & performance metal & substrate grades surface quality 3 LIGHTWEIGHT 2 2 Process optimized resistance of materials conditions & automation curing parameters 3 Engineering modeling & design numerical analysis testing & simulation Lightweight design is a result of cooperating disciplines 7

8 Market Trends & Requirements Automotive Body Structure Assembly Lightweight CO 2 Emission Targets Mech. Performance Env. Durability Robust Application Process Integration E-Mobility New BIW architectures MATERIAL PROCESS Alu, Steel Grades & Multi-Substrates Impact Peel & Increased Flexibility Low Temp Cure & Humidity Resistance Wash-off Resistance & Weldability Bonding & Thermal Cond. Strong Simulation & ENGINEERING Base Improve Bond Durability of Structural Adhesives for Lightweight Mat. 8

9 MATERIAL: Metal grades Bonding ZnMgAl Steels HDG 1.0% Al 1.0% Mg 2.5% Al 1.5% Mg 2.0% Al 2.0% Mg Cross section Steel Producer Trade Name Zn [wt.%] Mg [wt.%] Al [wt.%] Top surface view Thyssen-Krupp Ecoprotect Tata Steel Magizinc Voestalpine Corrender Nippon Steel SuperZinc Arcelor Mittal Magnelis

10 MATERIAL: Metal grades Optimization of Adhesion Properties on ZnMgAl Steels Increasing polarity of polymer matrix Lap Shear Strength DIN EN MPa 29.2 MPa 31.3 MPa Key: Understanding substrate-adhesive interface/surface chemistry 10

11 Agenda 1. Substrate Technology & Bonding 2. New Structural Adhesive Solutions 3. Mix Materials Bonding 4. Q & A 11

12 Benefits of Structural Bonding Crash simulation using box beams Deformation Energy [J/cm] spotwelded (26 sw) bonded Accepted benefits of structural bonding Improved stiffness of car body assemblies Up to 25% increase of energy absorption in the metal structures Increased fatigue durability Bonding of different substrates possible Good acoustic & vibration damping 12

13 MATERIAL: Metal grades Stress Durability Testing for Aluminum Joints Customer Case Stress Durability = ageing cycles under static load APGE cycles AL 5754 AL 6111 TEROSON EP 5015 specification minimum Lap Shear Specimen 2.4 kn static load APGE ageing cycle 0.25 hr NaCl immersion 1.75 hr dry heat 22.0 hr 50 C, 90% RH Source: Ford 13

14 MATERIAL: Impact Resistant Structural Bonding Over the Full Temperature Range 60 Impact Peel [N/mm] C +23 C +80 C TEROSON EP 5018 DIN ISO 11343; Hyundai MS mm CRS, 2 m/s Highly Crash Durable Structural Adhesive Core-Shell Toughening Technology 14

15 MATERIAL: Impact Resistance New Epoxy-based Crash Durable Adhesive TEROSON EP 5090 Lap Shear Strength GI Daimler; 0.75 mm C, DIN EN 1465 Impact Peel RT CRS 1405, 0,8 mm C, DIN ISO T-Peel GI Daimler, mm C, DIN EN 1464 Young s modulus C, DIN Elongation at Break C, DIN MPa 100% CF 34 N/mm 100% CF 11 N/mm 100% CF 2100 MPa 6% High crash performance down to -40 C Improved stiffness Improved retention of properties under humidity ageing Excellent adhesion on various ZnMgAl grades 15

16 MATERIAL: Semi-Crash Adhesive Rubber-based Hemflange Adhesive for Aluminum Bonding Lap Shear Strength AL 5000 (Etalon); 2 mm C, DIN EN 1465 Impact Peel RT CRS 1405, 0,75 mm C, DIN ISO T-Peel AL 5000 (Etalon), 2 mm C, DIN EN 1464 Elongation at Break C, DIN TEROSON RB MPa 100 % CF 15 N/mm 100 % CF 5 N/mm 100 % CF 45 % Interesting balance of performance & cost Semi-crash performance based on rubber-based for Hemflange Excellent retention of properties under Cataplasma durability conditions Only 9% lap shear strength loss after H14 16

17 MATERIAL: Multi-substrate Bonding New Epoxy-based Hemflange Adhesive for Closures TEROSON EP 5030 Lap Shear Strength GI Daimler; 0.75 mm C, DIN EN 1465 Impact Peel RT CRS 1405, 0,8 mm C, DIN ISO T-Peel GI Daimler, mm C, DIN EN 1464 Young s modulus C, DIN Elongation at Break C, DIN MPa 100 % CF 19 N/mm 100 % CF 7 N/mm 100 % CF 300 MPa 60 % Crash Performance High Elongation at break: 60% Delivery with glass beads optional Suitable for multi-substrate bonding 17

18 PROCESS: Wash-Off Resistance Bead stability via control over yield point & thixotropy Impingement resistance via control over oil absorption & surface wetting 10 mm 18

19 PROCESS: Water Uptake High Humidity Resistance 72h open bead Original Optimization Crash durable epoxy adhesive * Mixed bonding: HDG - H420+Z100 (1,2 mm) ; EG - HC450X+ZE75/75 (1,0 mm) C Improvement of humidity resistance (72 hours open bead at 23 C and 80% RH) Reduction of blistering Loss of strength after humidity < 10% Increase of Lap Shear Strength 19

20 Agenda 1. Substrate Technology & Bonding 2. New Structural Adhesive Solutions 3. Mix Materials Bonding 4. Q & A 20

21 Challenges in Structural Bonding of Lightweight Designs Mixed Material Body Technical Challenges Adhesion on dissimilar substrates CTE mismatch situations Corrosion (e.g. Alu CRP) Bonding without surface preparation Curing speed suitable for large series Need fundamental understanding of load cases for bonded joints and substrates 21

22 MATERIAL: CTE Effects in Multi-Material Structures Multi-Material structures during the service life Can we predict the structure response to temperature changes? How do the CTE mismatch effects during manufacturing affect the structural performance during service life? Can design/ material changes be developed to minimize the above effects? 22

23 Composite bonding solution Developed for lightweighting with multi-substrates [Strength N/mm 2 ] Structural bonding Product Technology Key Properties LOCTITE EA K Epoxy Modulus: 1500 MPa Shear strength: 25 MPa Elongation: 15 % 1K/2K epoxies 2K PU 1K PU acrylates Elastic bonding New PU or silane-modified polymers Sealing Product Technology Key Properties EPON 5018 Product Technology Key Properties LOCTITE UK K Epoxy 2K Polyurethanes Modulus: 1500 MPa Shear strength: 40 MPa Elongation: 45% Modulus: 340 MPa Shear strength: 24 MPa Elongation: 100 % Elongation [%] New structural adhesives for multi-substrate bonding and CTE challenges 23

24 On-vehicle visual detection of multi-substrate effects Collaboration with Clemson University, Greenville Visual Detection System: GOM Aramis Online information of strain distribution during lap shear test Lap Shear Specimen: Speckled coating at joint area 24

25 On-vehicle visual detection of multi-substrate effects Extension to oven curing process inside Instron Equipment 25

26 Adhesives Portfolio for Multimaterial Designs Young s Modulus of Adhesive [MPa] Stiffness Epoxy Metal Bonding Crash Epoxy Flexibilized Epoxy Multimaterial High Modulus Polyurethane Composites / Thermoplastics Standard Polyurethane Glass, PP Elongation At Break 1-5 % 5-20 % % % 26

27 Summary Lightweight design is a result of cooperating disciplines of materials, process and engineering Adhesive bonding is the key joining technology for multimaterial lightweight body structure design Simulation models give greater assurance that CTE can be managed with application-targeted adhesives Henkel provides an integrated technology offering including a unique substrate, application process and engineering know-how, together with an innovative structural adhesives portfolio 27

28 Agenda 1. Substrate Technology & Bonding 2. New Structural Adhesive Solutions 3. Mix Materials Bonding 4. Q & A 28

29 Thank you!