SEED: A NEW PROCESS FOR SEMI-SOLID FORMING

AbstractA new method for the preparation of feedstock for semi-solid forming processes is described. The process, dubbed SEED (Swirled Enthalpy Equilibration Device), consists of two steps: 1- the extraction of a controlled quantity of enthalpy from the molten metal charge in order to generate a liquid/solid slurry and 2- draining away the excess liquid in order to form a compact, self-supporting slug which can then be handled and formed under pressure. Using this approach it is unnecessary to measure the temperature of the material during processing and a wide range of alloys can be processed with ease. This paper describes the features of the process and the microstructures obtained using a variety of aluminum alloys.On decrit une nouvelle methode de preparation de la charge d’alimentation pour traitements de mise en forme a l’etat demi-solide. Le traitement, que l’on appelle SEED (d’apres les mots anglais pour ‘dispositif d’equilibration de l’enthalpie en tourbillon’), consiste en deux etapes: 1 – l’ex...