Testing of pyrotechnic compositions in closed vessel

In MP (multipurpose) munitions the nose cap is filled with a pyrotechnic composition that, when it sees certain stimuli, ignite and start burning. This burning is important for how the munitions will function. Compositions based on aluminium, magnesium and aluminium /magnesium powders in combination with potassium perchlorate have been tested. Compositions with a loading density of up to 0.6 g/cm3 have been tested in a 150 cm3 Closed Vessel, and pressure- time curves have been recorded. The tested compositions have different burn rates and ignitability. In addition to the experimentally measured the pressures, we have done some theoretical calculations of the expected pressures by use of the thermochemical code Cheetah.