Finite element modelling and experiments for shaping nuclear powder pellets, application in technological tool developments to minimize damage during ejection, and geometrical tolerances

Die pressing and sintering processes are used in the fabrication of fuel with minor actinides. Perfect cylindrical sintered pellets must be directly obtained by the current processes with take into account the slight heterogeneities of the density, which ones are present in the green body as a result of frictional forces between powder and die. FEM of the compaction stage has been used to simulate the die pressing stage of nuclear oxide powders and to predict the green density distributions. An ejection method with or without profile correction in the die has been used to removing the die radially. (authors)