Aging Mechanism of Zirconium Potassium Perchlorate Charge in Pyrotechnic Mechanical Devices

Lee, Junwoo; Choi, Kyoungwon; Ryu, Seung Un; Ahn, Gil Hwan; Paik, Jong Gyu; Ryu, Byungtae; Won, Yong Sun

doi:10.1166/nnl.2018.2660

Cited by 5 publications

(9 citation statements)

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“…Most recently, Lee et al . 22 investigated ZPP’s ageing mechanism under a 100% RH condition, where they focused primarily on the oxidation of Zr during such a limited aging condition without providing the relevant kinetic analyses of aging ZPP associated with particular reaction processes.…”

Section: Introductionmentioning

confidence: 99%

Towards understanding the effects of heat and humidity on ageing of a NASA standard pyrotechnic igniter

Jang

Yoh

2019

Sci Rep

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Ageing of pyrotechnic substance, primarily fuel oxidisation, can cause changes in composition that degrade their performance. This study investigates the effect of ageing on zirconium potassium perchlorate (ZPP), a widely used NASA Standard Initiator. Although prior studies have investigated the effects of accelerated ageing on ZPP, this is the first to conduct kinetic analyses at different relative humidity (RH) levels. Here, both thermal and kinetic analyses are conducted for a variety of hygrothermal ageing cases in order to replicate the natural ageing process. X-ray photoelectron spectroscopy (XPS) results reveal that oxidant levels drop and zirconium dioxide levels rise as ZPP ages. Lower heats of reaction and increases in activation energy were also observed under the RH conditions. Calculations using van’t Hoff equation indicate that moisture shortened the lifespan of the unaged ZPP up to about 85% under extreme RH conditions, while significantly deteriorating the heat of reaction, sensitivity, and thus increased the risk of a misfire.

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Section: Introductionmentioning

confidence: 99%

Towards understanding the effects of heat and humidity on ageing of a NASA standard pyrotechnic igniter

Jang

Yoh

2019

Sci Rep

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“…Meanwhile, we conducted our experimental study on the aging of BKNO3 and ZPP by exposing them to water vapor (H2O) in an accelerated aging condition with high RH (relative humidity) Meanwhile, we conducted our experimental study on the aging of BKNO 3 and ZPP by exposing them to water vapor (H 2 O) in an accelerated aging condition with high RH (relative humidity) [17,18]. DSC (differential scanning calorimetry)-based thermal analysis confirmed the reaction (or explosive) energy decrease with the duration of exposure to a highly humid atmosphere, and TEM (transmission electron microscopy)-EDS (energy dispersive spectroscopy) specified the gradual growth of an oxide layer on the surface of B and Zr-metallic fuels of BKNO 3 and ZPP, respectively.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Analysis on the Aging of THPP, ZPP and BKNO3 Explosive Charges in PMDs

et al. 2019

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The aging of explosive charges in pyrotechnic mechanical devices (PMDs) significantly affects the reliability of their performance. Aging decreases the explosive power of explosive charges via pre-oxidation by external sources of oxygen. In this study, the flame temperature was calculated based on the amount of added oxygen source, and the effect of aging was quantified in terms of the performance of explosive charges. Three primary explosive charges (THPP, ZPP, and BKNO3) were selected, and the explosion was assumed to have occurred in a closed adiabatic system. The flame temperature decreased with increasing oxygen addition, suggesting that the aging decreased the pressure exerted by the PMDs. The explosive power decreased in the following order: ZPP >> THPP > BKNO3 (4100 >> 3260 > 3050 K), and it was decreased by aging as follows: ZPP >> BKNO3 > THPP (802 >> 219 > 95 K per mole of added water). As a result, ZPP is appropriate for the generation of the huge thrust of PMDs despite its increased susceptibility to aging, while THPP is superior for reliable PMD performance.

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“…Recently, we have studied how the aging of BKNO 3 and ZPP is affected by internal and external factors [7,8]. It turned out that internal factors such as spontaneous pre-reactions have no effect, but pre-oxidations of fuels (B and Zr) by external oxygen source is the key aging mechanism of explosive charges.…”

Section: Introductionmentioning

confidence: 99%

“…It turned out that internal factors such as spontaneous pre-reactions have no effect, but pre-oxidations of fuels (B and Zr) by external oxygen source is the key aging mechanism of explosive charges. According to AKTS (advanced kinetics and technology solutions) simulations, any spontaneous pre-reaction such as laminac (a polymer binder used for integrating metal and oxidizer in explosive charges) decomposition would not occur in less than 500 years even at a storage temperature of 120 • C [7,8]. Meanwhile, TEM (transmission electron microscopy)-EDS (energy dispersion spectroscopy) and XPS (X-ray photoelectron spectroscopy) studies confirmed the formation of oxide shells on the surface of fuels and their growth with time under accelerated aging conditions [7,8].…”

Section: Introductionmentioning

confidence: 99%

“…According to AKTS (advanced kinetics and technology solutions) simulations, any spontaneous pre-reaction such as laminac (a polymer binder used for integrating metal and oxidizer in explosive charges) decomposition would not occur in less than 500 years even at a storage temperature of 120 • C [7,8]. Meanwhile, TEM (transmission electron microscopy)-EDS (energy dispersion spectroscopy) and XPS (X-ray photoelectron spectroscopy) studies confirmed the formation of oxide shells on the surface of fuels and their growth with time under accelerated aging conditions [7,8]. A substantial decrease of relative heat (18% and 40% for BKNO 3 and ZPP, respectively) was also detected by DSC (differential scanning calorimetry) measurements for 16-week aged samples under accelerated aging conditions, confirming that the aging of explosive charges is mostly affected by extra oxygen sources, such as moisture [7,8].…”

Section: Introductionmentioning

confidence: 99%

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A Combined Study of TEM-EDS/XPS and Molecular Modeling on the Aging of THPP, ZPP, and BKNO3 Explosive Charges in PMDs under Accelerated Aging Conditions

et al. 2019

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The aging mechanism of explosive charges in pyrotechnic mechanical devices (PMDs) is pre-oxidations of their fuels (TiH2 for THPP, Zr for ZPP, and B for BKNO3) by external oxygen. The effect of water on the aging of explosive charges was thus investigated by TEM-EDS/XPS and DFT-based molecular modeling under accelerated aging with 71 °C and 100% relative humidity. The formation of oxide shell and its thickness on the surface of fuels by the aging were observed by TEM-EDS. It failed to detect any oxide on the surface of TiH2 (no sign of Ti-O peaks in XPS) regardless of the aging time, while the thickness of oxide shell increases linearly with the time for ZPP and is saturated at a certain point for BKNO3. It suggested that THPP is highly robust to aging compared to the others (the order of THPP >> BKNO3 > ZPP). Then, DFT-based vacuum slab calculations visualized the diffusion of oxygen from the surface of fuels into the interior, confirming that the activation barrier for the oxygen diffusion is much lower for Zr and B than TiH2 (37, 107, and 512 kcal/mol for Zr, B, and TiH2, respectively), in agreement with experimental results.

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Aging Mechanism of Zirconium Potassium Perchlorate Charge in Pyrotechnic Mechanical Devices

Cited by 5 publications

References 0 publications

Towards understanding the effects of heat and humidity on ageing of a NASA standard pyrotechnic igniter

Towards understanding the effects of heat and humidity on ageing of a NASA standard pyrotechnic igniter

Thermodynamic Analysis on the Aging of THPP, ZPP and BKNO3 Explosive Charges in PMDs

A Combined Study of TEM-EDS/XPS and Molecular Modeling on the Aging of THPP, ZPP, and BKNO3 Explosive Charges in PMDs under Accelerated Aging Conditions

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