A flat disk having differing material properties in the inner and outer regions, resulting in varying dynamic material behavior during explosion deformation and a process for making the same. In particular, the outer regions of the flat disk produced, have a greater material hardness than the central regions of the disk.

Pyrotechnic charge, with a short combustion time, comprising inclined plates of propellant and deflectors, and a propulsion system using a charge of this type. The pyrotechnic charge is intended especially for use in a propulsion system for acceleration, and it comprises a set of plates of solid propellant, which plates are arranged approximately parallel to one another and provide at least one longitudinal channel for discharging the combustion gases in the direction of the nozzle of the propulsion system. In order to achieve a very high flow rate of gas without causing breakage of the plates of propellant, the plates of propellant (6) are inclined towards the longitudinal channel, and the charge comprises deflectors (5) which are arranged approximately parallel to the plates of propellant and which possess, in a longitudinal cross-section of the charge, a length which is equal to or greater than the length of the plates of propellant.

The present invention resides in a body of material which is ignitable to generate a gas for inflating an air bag. The body of material comprises at least two layers of ignitable gas generating material which are pressed together. One of the layers comprises a nitrogen generating composition which is easily ignited and burns rapidly. The other of the layers comprises a nitrogen generating composition which is less easily ignited and burns less rapidly than the one layer.

A hybrid rocket motor having enhanced fuel combustion efficiency is disclosed which includes a plurality of axially aligned fuel grains having multiple axial perforations. The fuel grains are rotated or canted relative to adjacent fuel grains such that the multiple axial perforations are offset.