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Fracture Analysis of Competing Failure Modes of Aluminum-CFRP Joints Using Three-Layer Titanium Laminates as Transition


The structural properties of lightweight constructions can be adapted to specific local requirements using multi-material designs. Aluminum alloys and carbon fiber-reinforced plastics (CFRP) are materials of great interest requiring suitable joining techniques in order to transfer the advantages of combining the materials to structural benefits. Thus, the research group “Schwarz-Silber” investigates novel concepts to enable frontal aluminum-CFRP joints using transition structures. In the foil concept titanium foils are used as transition elements. Specimens have been produced using three-layer titanium laminates. In tensile tests, three failure locations have been observed: (1) Al-Ti seam, (2) Ti-CFRP hybrid laminate, and (3) CFRP laminate. In this paper, the fracture mechanisms of these failure modes are investigated by analyzing metallographic micrographs and fracture surfaces as well as by correlating load-displacement curves to video imaging of tensile tests. The results show that the cracking of the CFRP layers can be traced back to an assembly error. The laminate character of the titanium part tends to reduce the Al-Ti seam strength. However, two sub-joint tests demonstrate that the Al-Ti seam can endure loads up to 9.5 kN. The ductile failure behavior of the Ti-CFRP hybrid laminates is caused by plastic deformations of the titanium laminate liners.

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  1. 1.

    R. Kocik, T. Vugrin, and Seefeld T., Laserstrahlschweißen Im Flugzeugbau: Stand und künftige Anwendungen (laser beam welding in the aircraft industry: status and future applications), 5. Laser-Anwenderforum, 2006. (in German)

  2. 2.

    K. Mori, N. Bay, L. Fratini, F. Micari, and A.E. Tekkaya, Joining By Plastic Deformation, CIRP Ann., 2013, 62(2), p 673–694

    Article  Google Scholar 

  3. 3.

    J. Schumacher, A. Irretier, R. Kocik, R. Tinscher, O. Kessler, N. Sotirov, and H. Bomas, Investigation of Laser-Beam Joined Titanium-Aluminum Hybrid Structures, Applied Production Technology Apt’07, p 149–160.

  4. 4.

    F. Fischer, L. Romoli, and R. Kling, Laser-Based Repair of Carbon Fiber Reinforced Plastics, CIRP Ann., 2010, 59(1), p 203–206

    Article  Google Scholar 

  5. 5.

    D. Bashford, Basic Aspects of Joining Technology For Fibre Reinforced Plastics, 1986.

  6. 6.

    P. Davies, W.J. Cantwell, P.-Y. Jar, P.-E. Bourban, V. Zysman, and H.H. Kausch, Joining and Repair of a Carbon Fibre-Reinforced Thermoplastic, Composites, 1991, 22(6), p 425–431

    Article  Google Scholar 

  7. 7.

    G. Di Franco, L. Fratini, and A. Pasta, Analysis of the Mechanical Performance of Hybrid (Spr/Bonded) Single-Lap Joints Between CFRP Panels and Aluminum Blanks, Int. J. Adhes. Adhes., 2013, 41, p 24–32

    Article  Google Scholar 

  8. 8.

    S. Ucsnik, M. Scheerer, S. Zaremba, and D. Pahr, Experimental Investigation of a Novel Hybrid Metal-Composite Joining Technology, Compos. Part A, 2010, 41(3), p 369–374

    Article  Google Scholar 

  9. 9.

    M. Menacher, C. Leisen, and D. Drummer, Formschlüssiges Fügen von Metallen mit Faserverbundkunststoffen mittels Vibrationsschweißtechnik (form-closed joining of metals and fiber reinforced plastics by vibration welding technology), Große Schweißtechnische Tagung, DVS Media, 2013, p 183–187. (in German)

  10. 10.

    F. Balle, S. Huxhold, G. Wagner, and D. Eifler, Damage Monitoring of Ultrasonically Welded Aluminum/ Cfrp-Joints By Electrical Resistance Measurements, 11th International Conference on the Mechanical Behavior of Materials (ICM11), 2011, Vol. 10(0), p 433–438.

  11. 11.

    S.M. Goushegir, J.F. dos Santos, and S.T. Amancio-Filho, Friction Spot Joining of Aluminum Aa2024/Carbon-Fiber Reinforced Poly(Phenylene Sulfide) Composite Single Lap Joints: Microstructure and Mechanical Performance, Mater. Des., 2014, 54, p 196–206

    Article  Google Scholar 

  12. 12.

    R. Velthuis, M.P. Kötter, P.L. Geiss, P. Mitschang, and A.K. Schlarb, Leichtbau aus Metall und Faser-Kunststoff-Verbunden (light weight design using metals and fiber reinforced plastics), Kunststoffe, 2007, 11(11), p 52–56 (in German)

    Google Scholar 

  13. 13.

    K.-W. Jung, Y. Kawahito, M. Takahashi, and S. Katayama, Laser Direct Joining of Carbon Fiber Reinforced Plastic to Aluminum Alloy, J. Laser Appl., 2013, 25(3), p 32003-1–32003-6

    Article  Google Scholar 

  14. 14.

    P. Woizeschke and V. Wottschel, Recent Developments For Laser Beam Joining of CFRP-Aluminum Structures, Mater. Procedia, 2013, 2, p 250–258

    Article  Google Scholar 

  15. 15.

    P. Woizeschke, J. Schumacher, U. Specht, A. Lang, and F. Vollertsen, Joining of Aluminum and CFRP Parts Using Titanium Foils As Transition Elements, Presented at Euro Hybrid—Materials and Structures 2014, April 10–11, 2014 Stade, Germany, p 69–75.

  16. 16.

    J. Clausen, U. Specht, M. Busse, A. Lang, and J. Sanders, Integration of Glass Fibre Structures in Aluminium Cast Parts For CFRP Aluminium Transition Structures, Mater. Procedia, 2013, 2, p 197–203

    Article  Google Scholar 

  17. 17.

    J. Schumacher, B. Clausen, and H.-W. Zoch, Strength and Failure Behaviour of Carbon Fibre Reinforced Plastics (CFRP)-Aluminium Seam Structures, Mat.-wiss. u. Werkstofftech, 2014, 45(12), p 1108–1115

    Article  Google Scholar 

  18. 18.

    J. Köhler, T. Grove, O. Maiß, and B. Denkena, Residual Stresses in Milled Titanium Parts, 1st CIRP Global Web Conference: Interdisciplinary Research in Production Engineering (CIRPE2012), 2012, Vol. 2(0), p 79–82.

  19. 19.

    P. Woizeschke and F. Vollertsen, Laser Joining of Aluminum and CFRP Parts Using Titanium Transition Structures, Presented at Annual Assembly 2013 of the International Institute of Welding (IIW) in Commission IV Power Beam Processes, Essen, Germany, 2013, p IIW document number: IV-1145-13 (online).

  20. 20.

    B. Majumdar, R. Galun, A. Weisheit, and B.L. Mordike, Formation of a Crack-Free Joint Between Ti Alloy and Al Alloy By Using a High-Power Co2 Laser, J. Mater. Sci., 1997, 32, p 6191

    Article  Google Scholar 

  21. 21.

    Y. Chen, S. Chen, and L. Li, Influence of Interfacial Reaction Layer Morphologies on Crack Initiation and Propagation in Ti/Al Joint By Laser Welding-Brazing, Mater. Des., 2010, 31(1), p 227–233

    Article  Google Scholar 

  22. 22.

    E.S. Ege, O.T. Inal, and C.A. Zimmerly, Response Surface Study on Production of Explosively-Welded Aluminum-Titanium Laminates, J. Mater. Sci., 1998, 33(22), p 5327–5338

    Article  Google Scholar 

  23. 23.

    J. Wilden and J.P. Bergmann, Manufacturing of Titanium/Aluminium and Titanium/Steel Joints by Means of Diffusion Welding, Weld. Cut., 2004, 3, p 285–290

    Google Scholar 

  24. 24.

    T. Takemoto and I. Okamoto, Intermetallic Compounds Formed During Brazing of Titanium With Aluminium Filler Metals, J. Mater. Sci., 1988, 23, p 1301

    Article  Google Scholar 

  25. 25.

    M. Kreimeyer and F. Vollertsen, Processing Titanium-Aluminum Hybrid Joints For Aircraft Applications, Proceedings of the Third International WLT-Conference on Lasers in Manufacturing (LiM2005), 2005, p 73–78.

  26. 26.

    Z. Song, K. Nakata, A. Wu, and J. Liao, Interfacial Microstructure and Mechanical Property of Ti6al4v/A6061 Dissimilar Joint by Direct Laser Brazing Without Filler Metal and Groove, J. Mater. Sci. Eng. A, 2013, 560, p 111–120

    Article  Google Scholar 

  27. 27.

    R. Kocik, Analyse und Bewertung der mechanisch-technologischen Eigenschaften von geschweißten Mischverbindungen aus Aluminium und Titan (analysis and evaluation of the mechanical properties of welded hybrid joints between aluminum and titanium), PhD Thesis, Shaker, 2009. (in German)

  28. 28.

    S.H. Chen, L.Q. Li, and Y.B. Chen, Interfacial Reaction Mode and Its Influence on Tensile Strength in Laser Joining Al Alloy to Ti Alloy, Mater. Sci. Tech., 2010, 26(2), p 230–235

    Article  Google Scholar 

  29. 29.

    P. Naghipour, K. Schulze, J. Hausmann, and M. Bartsch, Numerical and Experimental Investigation on Lap Shear Fracture of Al/CFRP Laminates, Compos. Sci. Technol., 2012, 72(14), p 1718–1724

    Article  Google Scholar 

  30. 30.

    G.W. Critchlow and D.M. Brewis, Review of Surface Pretreatments For Titanium Alloys, Int. J. Adhes. Adhes., 1995, 15(3), p 161–172

    Article  Google Scholar 

  31. 31.

    P. Molitor, V. Barron, and T. Young, Surface Treatment of Titanium For Adhesive Bonding to Polymer Composites: a Review, Int. J. Adhes. Adhes., 2001, 21(2), p 129–136

    Article  Google Scholar 

  32. 32.

    S. Zimmermann, U. Specht, L. Spieß, H. Romanus, S. Krischok, M. Himmerlich, and J. Ihde, Improved Adhesion at Titanium Surfaces via Laser-Induced Surface Oxidation and Roughening, Mater. Sci. Eng. A, 2012, 558, p 755–760

    Article  Google Scholar 

  33. 33.

    U. Specht, J. Ihde, and B. Mayer, Laser Induced Nano-Porous Ti-O-Layers For Durable Titanium Adhesive Bonding, Mat.-wiss. u. Werkstofftech, 2014, 45(12), p 1116–1122

    Article  Google Scholar 

  34. 34.

    J. Adamowski, C. Gambaro, E. Lertora, M. Ponte, and M. Szkodo, Analysis of FSW Welds Made of Aluminium Alloy AW6082-T6, Arch. Mater. Sci. Eng., 2007, 28(8), p 453–460

    Google Scholar 

  35. 35.

    C. Casavola, C. Pappalettere, and F. Tattoli, Experimental and Numerical Study of Static and Fatigue Properties of Titanium Alloy Welded Joints, Mech. Mater., 2009, 41(3), p 231–243

    Article  Google Scholar 

  36. 36.

    G. Belingardi, L. Goglio, and A. Tarditi, Investigating the Effect of Spew and Chamfer Size on the Stresses in Metal/Plastics Adhesive Joints, Int. J. Adhes. Adhes., 2002, 22(4), p 273–282

    Article  Google Scholar 

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The authors gratefully acknowledge financial support of this work by the German Research Foundation (DFG FOR1224). The authors also thank all their colleagues within the research group “Schwarz-Silber” ( for the support and cooperation, especially U. Specht (IFAM) for contributing the laser pre-treatments of the titanium foils, A. Lang (FIBRE) for manufacturing the titanium-CFRP hybrid laminates, and J. Schumacher (IWT) for carrying out the tensile tests of the Al-Ti-CFRP test items. The work at BIAS—Bremer Institut für angewandte Strahltechnik GmbH ( was accomplished within the Center of Competence for Welding of Aluminum Alloys-Centr-Al. The “BIAS ID” numbers are part of the figures and allow the retraceability of the results with respect to mandatory documentation required by the funding organization.

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Woizeschke, P., Vollertsen, F. Fracture Analysis of Competing Failure Modes of Aluminum-CFRP Joints Using Three-Layer Titanium Laminates as Transition. J. of Materi Eng and Perform 24, 3558–3572 (2015).

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  • aluminum
  • composites
  • failure analysis
  • hybrid structure
  • joining
  • multi-material design
  • titanium