Flow forming and flow formability of alloys used in missile systems: characterization, influence of heat treatments and determination of the maximum reduction rate

The flow forming process has been developed after the Second World War, but the principle of the process is known for a long time. Flow forming is a process for manufacturing complex lightweight components which are increasing required in different industries. In free market economies, on the one hand it is necessary to meet the growing demand, on the other hand it is also necessary to reduce time factor to manufacture this type of high quality component. As this process is relatively new, only a few works have been carried out in this field. These works have been focused on steel and the determination of properties after flow forming such as mechanical properties, texturing, residual stress and etc. The studies on flow formability of other alloys are not yet fully started and there is a gap. Till yet, the flow forming has been carried out from a preform which was manufactured using classical machining. In this study, a test to perform the flow forming of a roll bended and laser welded preform is described. The influence of flow forming in geometrical properties is also tested. Since flow forming is a complex and sensitive process, the characteristics of deformation is not an easy task to complete. The aim of this research work is to fill partially the gaps listed above and to acquire more knowledge on the flow forming process. It is a challenging task as the missile parts ought to have minimum mass, very high specific strength, minimal dimensional tolerances and perfect surface finish to ensure excellent performance and reliability. My research work is focused on three themes: - Flow turning of mechanically rolled and welded preforms - Flow turning of aluminium alloys - Influence of multiple pass in texturing and geometrical properties