Journal of Materials Engineering and Performance

, Volume 13, Issue 6, pp 678–682 | Cite as

Advances in fabricating superplastically formed and diffusion bonded components for aerospace structures

  • Larry D. Hefti
Superplastic Forming


Superplastic forming and diffusion bonding (SPF/DB) production hardware is being fabricated today for aerospace applications. Metal tooling is being used to bring the titanium sheets into contact so diffusion bonding can occur. However, due to material sheet and tooling tolerances, good bond quality is difficult to achieve over large areas. A better method for achieving DB is to use “stop-off” inside sealed sheets of titanium, which constitutes a pack, and then the pack is bonded using external gas pressure. A good method for heating the pack for this process is to use induction heating. Components using “stop-off” that were diffusion bonded first and then superplastically formed have shown much better bond quality than components that were produced using matched metal tooling. This type of tooling has been successful at bonding small areas as long as the exerted pressure is concentrated on the area where bonding is required. Finite element modeling is providing weight effect solutions for titanium SPF/DB aerospace structures.


diffusion bonding finite element modeling induction heating metal tooling stop-off superplastic forming titanium 


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  1. 1.
    D.W. Schulz, SPF/DB Applications for Advanced Turbomachinery, paper 9, Effective Applications of Superplastic Forming and Diffusion Bonding for the Engineering Specialist, SME, 1988Google Scholar
  2. 2.
    E.J. Tuegel, M.O. Pruitt, L.D. Hefti, SPF/DB Takes Off, Adv. Mater. Process. Inc. Met. Prog., Vol 136 (No. 1), 1989, p 36–41Google Scholar
  3. 3.
    L.D. Hefti, Applications of SPF and SPF/DB in Fighter Aircraft Structures, paper 10, Effective Applications of Superplastic Forming and Diffusion Bonding for the Engineering Specialist, SME, 1988Google Scholar
  4. 4.
    J. Pilling and N. Ridley, Superplasticity in Crystalline Solids, 1st ed., Institute of Materials, 1989, p 214Google Scholar
  5. 5.
    D. Stephens, Designing for Superplastic Alloys, AGARD Lecture Series No. 154, Superplasticity, AGARD, 1987, p 7-1–1-37Google Scholar
  6. 6.
    M. Hayase, R.C. Ecklund, R.J. Walkington, J.B. Hughes, and N.R. Williams, Method of Fabricating Metallic Sandwich Structure, U.S. Patent 4,217,397, 1980Google Scholar
  7. 7.
    M.R. Matsen, J.A. Mittleider, R.T. Privett, and D.K. Dabelstein, System and Method for Controlling an Induction Heating Process, U.S. Patent 6,528,771, 2003Google Scholar
  8. 8.
    D.G. Sanders, A Production System Using Ceramic Die Technology for Superplastic Forming, Superplasticity in Advanced Materials ICSAM 2003, R.I. Todd, Ed., Trans Tech Publications, 2004, p 153–158Google Scholar
  9. 9.
    L.D. Hefti, Innovations in Fabricating Superplastically Formed Components, First and Second International Symposia on Superplasticity and Superplastic Forming Technology, D.G. Sanders and D.C. Dunand, Ed., ASM International, 2003, p 124–30Google Scholar
  10. 10.
    N. Rebelo and T.B. Wertheimer, Finite Element Simulation of Superplastic Forming, paper 1, Effective Applications of Superplastic Forming and Diffusion Bonding for the Engineering Specialist, SME, 1988Google Scholar
  11. 11.
    L.D. Hefti, Using Superplastic Forming as a Means of Achieving Cost Benefits as Well as Enhancing Aircraft Performance, High Performance Metallic Materials for Cost Sensitive Applications, F.H. Froes, E.Y. Chen, R.R. Boyer, E.M. Taleff, L. Lu, D.L. Zhang, C.M. WardClose, and D. Eliezer, Ed., TMS, 2002, p 65–72Google Scholar

Copyright information

© ASM International 2004

Authors and Affiliations

  • Larry D. Hefti
    • 1
  1. 1.The Boeing Company, Material & Process TechnologySeattle

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