Pulsed electromagnetic processing of metals

This Thesis is based on the concept of using an electromagnetic accelerator for metal forming, including cylindrical implosions and ‘flyer’ plate configurations. Although the present research is purely academic, a contact and a collaboration has been initially initiated with the well-known commercial company B-max (France), arguably the top manufacturer worldwide in the domain of magneto-forming. Unfortunately, when their CEO changed, they did not want any more to continue the collaboration. The below described research, which relates to my PhD, was mostly devoted to the technique of imploding metallic cylinders at high speeds with a high level of cylindrical homogeneity. This technique, that relates to the more general domain of magneto-forming of metals, has already been applied in various industrial applications, such as high-tech car manufacturing, fuel pin end closures for nuclear breeder reactors, avionics, outer space technology and others. The technique is very straightforward in concept and involves the supply of a strong pulsed current for driving a coil surrounding a metallic cylinder to be imploded. A current is induced by induction in the cylinder and the interaction between the two opposed currents produces a very strong radial force that is responsible for the implosion. Unique support for this experimental work was provided by a detailed 2-dimensional numerical code. The developed software reported here is capable of predicting the current and temperature distributions in the imploding cylinder and, very importantly, the imploding dynamics enabling the electromagnetic implosion system to be both accurately designed and controlled.