Spraying the perfect billet

In the billet spray-forming process, billet shape and positioning strongly influence billet solidification, and consequently end-product quality. Therefore, the ability to produce a billet of a desired shape and position is very important. Shape and positioning of a steady state billet surface depend, through an averaging procedure, on the atomiser scanner angle function. This paper approaches the problem of how to stably reconstruct the atomiser scanner angle function from a given set of ideal billet shapes. Mathematical features which make a billet shape ideal are discussed. A non-constrictive subclass of billet surfaces possessing these features is investigated. An algorithm is developed for calculating the scanner angle function which produces the perfect billet and finally numerical results are presented.