A non-calorimetric approach for investigating the moisture-induced ageing of a pyrotechnic delay material using spectroscopies

Abstract

The degradation of thermal properties due to ageing such as burning rate and exothermic heat release are unsolved issues faced during a long-term storage of the pyrotechnic substances. Accordingly, we employed various non-calorimetric methods to investigate the thermal performance of pyrotechnic delay, which is exposed to various moisture-rich conditions at extended durations. The chemical and physical changes in the compositions of a pyrotechnic delay comprised of metal fuel (Zr-Ni alloy) and oxidants (KClO4, BaCrO4) are analysed for four different relative humidity levels using X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope and laser-induced breakdown spectroscopy. The calculations using the NASA Chemical Equilibrium with Applications (CEA) software indicated that the heat of reaction for the components stored under the moisture-rich conditions is reduced by more than 50%. Unlike the conventional calorimetric analysis, the present non-calorimetric approach provided the compositional changes as well as the cause and effect of the relevant ageing process of pyrotechnic delay.

Towards a Deep Insight Into Thermal and Moisture Aging of Silicon‐Based Pyrotechnic Delay Composition Through a Combination of Spectroscopic Techniques – Principal Component Analysis Approaches

“…Similar behavior has also been reported in a recent publication from Ji-Hoon Ryu et al [25], where a pyrotechnic delay, comprised of metal-fuel (ZrÀ Ni alloy) and oxidants (KClO 4 , BaCrO 4 ), was subjected to moisture aging. They found out that the barium chromate (BaCrO 4 ) contained in a delay composition is considerably affected by the presence of humidity, which will induce the oxidation and dehydration of the chromate ions CrO 4…”

“…Several works published so far aimed at understanding the aging of pyrotechnic compositions [8,17,[22][23][24] under various aging conditions, i. e., temperature and humidity. Despite that, only a few of them have studied the aging of pyrotechnic delay compositions [8,10,16,25,26]. Yoh's research group has been quite involved in the research area concerning the aging of pyrotechnic delay compositions [10,16,25,26].…”

“…Despite that, only a few of them have studied the aging of pyrotechnic delay compositions [8,10,16,25,26]. Yoh's research group has been quite involved in the research area concerning the aging of pyrotechnic delay compositions [10,16,25,26]. They studied compositions based on zirconium and zirconium-nickel alloy as fuel together with potassium perchlorate (KClO 4 ), barium chromate (BaCrO 4 ), and iron oxide (Fe 2 O 3 ) as oxidizers [10,16].…”

“…However, several studies followed quite interesting approaches consisting of the use of non-calorimetric methods or spectroscopic techniques such as XRD, Raman, photoelectron spectroscopy, etc. to investigate the aging of such pyrotechnic compositions [22,23,25]. It was revealed that non-calorimetric approaches are highly suitable to study the compositional changes induced by such relevant aging processes within the studied pyrotechnics [22,23,25].…”

“…to investigate the aging of such pyrotechnic compositions [22,23,25]. It was revealed that non-calorimetric approaches are highly suitable to study the compositional changes induced by such relevant aging processes within the studied pyrotechnics [22,23,25].…”