Superplastic forming

Au is favorable for such MC formation at the ambient temperature, whereas the well-known ductile metals of Ag = 1,235 K), A1 T = 933.5 K), and Cu — 1,356 K) are unlikely to form extendable MCs though they could form superplastic NWs at the ambient temperatures. Although the electronic structure may need to be considered in making an MC [10], the operating temperature would be most critical. The high extensibility is apparent in the temperature range that corresponds to the quasi-molten state that is much softer and highly extendable than the bulk. 

The morphology of globular type is the most favourable when superplastic deformation is to occur in AI78wt%Zn alloy. This type of structure is formed by decomposition of the a solid solution a -> a + P However, plates usually dominate in the structure of this alloy. To obtain the non-plate or globular type, a special heat treatment is neccesary i.e. the optimal cooling rate as well as the temperature and time of ageing. 

Fig. 12. The scheme of the press for backward forming of cups m one action by means of the superplastic deformation mechanism. The deformation was done at temperature T = 523 K and at stamp velocity of about 1 mm/min.

Lockheed F-22 carbon fibre reinforced PEEK and PEI processed by the SuperPlastic Diaphragm Forming (SPDF) technique. 

A wing panel made of diffusion-bonded and superplastically formed titanium. 

For high-pressure applications in the hydrocarbon and chemical processing industries, a titanium compact heat exchanger has been developed by Rolls-Laval. This heat exchanger consists of diffusion-bonded channels that are created by superplastic forming of titanium plates (18). This heat exchanger can handle high pressure and corrosive fluids and is suitable for marine applications. 

Superplastic ceramics have several obvious potential advantages for commercial application. These include net size and shape forming and the possibility of forming complex components from initially flat sheets. Whilst the practical problems of forming at temperatures in excess of 1200°C obviously... 

Figure 6. Above a tool for the superplastic forging of titanium, made entirely from carbon/carbon composites (15) Below aircraft exhaust manifold formed from titanium by superplastic forging with the carbon/carbon tool.

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