Abstract
Several heterogeneous solid rocket propellants, of the broad family AP/metal/HTPB, were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano in cooperation with MACH I Inc. In general, they feature the same nominal composition, but different metals are investigated as fuel powders and contrasted to a conventional micrometric aluminum (30 mu m average grain size) taken as reference. Although the metal oxidation process follows a common set of events, aggregation and agglomeration phenomena near the burning surface may be noticeably different depending on the enforced operating conditions and details of the solid propellant formulation. Understanding of these effects opens the path to improved ballistic performance.