Superplastic Forming Manufacturing Technology Moves Towards the Twenty-First Century

Abstract

Superplastic Forming (SPF) of titanium alloys for military aviation hardware became a viable manufacturing technology in United States (U.S.) the early 1970's as an outgrowth of the Rockwell B-1 Bomber for the U.S. Air Force and in the United Kingdom during the development of the Concorde supersonic transport. Many early metallurgical studies of the Superplastic phenomenon were made prior to these efforts. However, the Built up Low cost Advanced Titanium Structure (BLATS) program sponsored by the U.S. government generated renewed interest and launched an entire new field of study for both the academic and industrial communities. The BLATS SPF related efforts were targeted primarily at the discovery and development of new superplastic titanium and aluminum alloys for structural aerospace applications. A limited amount of manufacturing development was accomplished, but the program did result in a SPF process that was commercially successful, albeit somewhat archaic and inefficient. Military airframes, such as the Boeing F-15E and Euro-Fighter 2000 have reported tremendous design gains by using SPF structures. Complex designs which make use of superplastic formed 6Al-4V titanium have now found their way into the mainstream of commercial aviation. Superplastic formed parts are now flying on every model of aircraft that is currently produced by Boeing. In general, SPF industrial manufacturing technology has lagged behind the development of advanced SPF materials. This has led to the current situation, in which the factories that must produce SPF and SPF/DB components are struggling to overcome a host of challenges. As we move towards the twenty-first century, the focus of SPF technology innovation is shifting. Commercial SPF research and development activities are moving away from the traditional objectives of advancing new materials and structural design development. This paper has been written to identify the many new categories of research that will be explored in the coming years. These areas include the following: ○ Development of High Temperature Oxide resistant and creep resistant CRES alloys for use in cast/machined dies ○ Lead Time: Fast die change methods, setup reduction ○ Inexpensive SPF press design and components ○ Cast ceramic tooling (fused silica and other materials).