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. T he dilution (with ZrO2) was varied from 0 to 80% and the pressure of the ga s 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 p rocess. In the absence of diluent, the first stage dominates, as reflected by temperature profiles. The combustion temperature and wave velocity incre ased with increasing gas pressure, leading to compaction of the temperature profiles. Changing the relative green density had a strong influence on th e combustion process as judged by the temperature profiles. Profiles of und iluted lower density samples exhibit the typical steep initial rise, but th ose of higher density samples show a slow rise to the maximum. (C) 2000 Els evier Science S.A. All rights reserved.