Process Control Challenges During the Manufacture of Large Superplastically Formed/Diffusion Bonded Structure 912195

This paper discusses technological aspects of the combined metal stretch and superplastic forming/diffusion bonding (SPF/DB) process applied to the manufacture of large and structurally complex engine nacelle components of the C-17 Advanced Military Airlifter. The manufacturing approach uses the McDonnell Douglas four-sheet SPF/DB process as the principal fabrication method, which in combination with the concurrent stretch is perceived as the most innovative and technologically advanced concept undertaken by the industry.
The component is a compound curvature titanium 6AI-4V weld assembly made up of four, 20 mm (0.75 inch) thick sandwich segments approximately 90 cm by 120 cm (3 feet by 4 feet) in size.
Also addressed are the engineering and manufacturing concepts, quality criteria, and the need for, and challenges of predicting and controlling the SPF/DB process, a prerequisite for the economic viability of the technology.
Among the many fabrication steps, the purchase of the raw material to final inspection, the SPF/DB process is considered a critical process which in the context of this dissertation, implies that the quality of the product is solely dependent on the execution of the process itself.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 40% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.