Abstract
Linear burning rate, thermal aualysis, temperature profile, flame structure and cryogenic burnability for the mixtures of sodium azide (SA) of different particle sizes (3.5 ΞΌm, 22 ΞΌm, and 67 ΞΌm), potassium perchlorate (KP) and with or without three kinds of burning catalysts (GeO~2~, Er~2~O~3~, and Y~2~O~3~) have been investigated. The linear burning rates increase with the KP content up to 33Wt% for similar SA particle size. The temperatureβtime histories in the vicinity of burning surface were obtained with 20 ΞΌm Type K thermocouple embedded in a Strand. The burning surface temperaturres of neat SA and of the SA/KP mixtures are nearly 350Β°C and 350Β°C βΌ 550Β°C, respectively, while the existence of the decomposition surface at 250 Β°C and condensed layer was suggested with SA/KP mixtures. In visual observation for the flame structure, the front of luminous flame zone appers to be in contact with the condensed phase surface. For example, however, the temperature profile suggests that there exists finitc distance from decomposition surface to flame front in the order of 0.05 mm βΌ 0.1 mm at 1 MPa for SA/KP = 80/20. The differential thermal analysis indicates that the tested catalysts have retarding effect on SA combustion, but a positive effect on neat KP decomposition in spite of being impotent for the burning rate increase of the SA/KP mixture. It was also found that SA strands containing appropatiae fractions of KP can hurn even in liquid nitrogen.