Shock-wave processing of powder mixtures

The effects of shock waves on the initiation of exothermic chemical reactions in mixtures of powders is explored experimentally and compared to thermal initiation at atmospheric pressure in this thesis. A model for calculation of the shock Hugoniot of non-reacting solid or powder mixtures up to moderate pressures using only static thermodynamic properties of the components is presented. It is shown that for a mixture, the conservation equations define a Hugoniot surface, and that the ratio of the thermal energy of the components determines where the shocked state of the mixture lies on this surface. This ratio, which may strongly affect shock-initiated chemical reactions and the properties of consolidated mixtures, is found to have only a minor effect on the Hugoniot of a mixture.;The initiation of reaction forming NiSi from elemental powders by shock waves of varying energy and pressure and by thermal initiation at atmospheric pressure was investigated. It was determined that a sharp energy threshold exists for reaction initiation. This threshold energy range heats the powder mixture to a temperature between 631 and 648;The conditions for the reaction forming Ti...