Combustion of zirconium powders in oxygen

The combustion of zirconium powders in air and oxygen was investigated as a function of gas pressure, level of dilution, and relative green density. The dilution (with ZrO2) was varied from 0 to 80% and the pressure of the gas was varied from 1 to 12 atm. The combustion process involves two stages, one related to the propagation of the wave and the other is an after-burn process. In the absence of diluent, the first stage dominates, as reflected by temperature profiles. The combustion temperature and wave velocity increased with increasing gas pressure, leading to compaction of the temperature profiles. Changing the relative green density had a strong influence on the combustion process as judged by the temperature profiles. Profiles of undiluted lower density samples exhibit the typical steep initial rise, but those of higher density samples show a slow rise to the maximum.