Accelerated-Aging Characteristics of B/KNO<sub>3</sub> Igniter Material

The aging properties of boron/potassium nitrate (B/KNO3) igniter were investigated using an accelerated aging test. Stabilization of the crystal structure of the oxidizer (KNO3) was attributed to degradation by aging. A well-known igniter material, B/KNO3 is used in solid propellants for aerospace applications. Because the ignition efficiency of this ignition agent decreases with prolonged storage, a variety of aging studies have been carried out to ensure its igniting reliability. Although most studies have investigated changes in the properties associated with aging, few studies have examined changes in the component materials as causes. The accelerated aging conditions used herein induced changes in the microstructure, crystal structure, and thermal properties of B/KNO3. In particular, the impact of KNO3 crystal structure change on igniter behavior was investigated.