THERMAL BEHAVIOR AND IGNITION OF HIGH-ENERGY MATERIALS CONTAINING B, ALB2, AND TIB2

The paper presents the results of ignition and thermal behavior for samples of high-energy materials (HEM) based on ammonium perchlorate (AP) and ammonium nitrate (AN), active binder and powders of Al, B, AlB2, and TiB2. A CO2 laser with a heat flux density range of 90-200 W/cm2 was used for studies of ignition. The activation energy and characteristics of ignition for the HEM samples were determined. Also, the ignition delay time and the surface temperature of the reaction layer during the heating and ignition for the HEM samples were determined. It was found that the complete replacement of micron-sized aluminum powder by amorphous boron in a HEM sample leads to a considerable decrease in the ignition delay time by a factor of 2.2-2.8 at the same heat flux density due to high chemical activity and the difference in the oxidation mechanisms of boron particles. The use of aluminum diboride in a HEM sample allows one to reduce the ignition delay time of a HEM sample by a factor of 1.7-2.2. The quasi-stationary ignition temperature is the same for the AlB2-based and AlB12-based HEM samples.

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Study on Laser Ignition Characteristics of NEPE Propellant

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.549.1037 ◽

2012 ◽

Vol 549 ◽

pp. 1037-1040

Author(s):

Guo Qiang Zhu ◽

Xiong Chen ◽

Chang Sheng Zhou ◽

Qi Jun Wu

Keyword(s):

Heat Flux ◽

Flux Density ◽

Ignition Delay ◽

Delay Time ◽

Heat Flux Density ◽

Ignition Delay Time ◽

Laser Ignition ◽

Ignition Process ◽

Laser Heat ◽

Nepe Propellant

The ignition process of NEPE propellant by a CO2 laser ignition system has been investigated experimentally. The effect of laser heat flux density on the ignition delay time of NEPE propellant was examined. The ignition delay time of NEPE propellant was decreased along with the increase of laser heat flux density. The effect of ignition heat flux density on ignition delay time decreases when the laser heat flux density is more than 290 W/cm2. This heat flux density value can be used as igniter design reference value. The ignition delay time increases dramatically along with the decrease of laser heat flux density when the laser heat flux density is lower.

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Зажигание борсодержащих высокоэнергетических материалов на основе окислителя и полимерного связующего

Журнал технической физики ◽

10.21883/jtf.2021.06.50861.329-20 ◽

2021 ◽

Vol 91 (6) ◽

pp. 926

Author(s):

А.Г. Коротких ◽

И.В. Сорокин ◽

К.В. Слюсарский ◽

В.А. Архипов

Keyword(s):

Ammonium Nitrate ◽

Ammonium Perchlorate ◽

Ignition Delay ◽

Delay Time ◽

Ignition Delay Time ◽

Pure Aluminum ◽

High Energy ◽

Metal Powders ◽

Energy Materials ◽

Constant Rate

The use of aluminum borides is a promising direction in the development of modern fuel compositions and aircraft. The paper presents experimental data on the kinetics of oxidation of micro-sized powders of aluminum, amorphous boron, aluminum borides AlB2 and AlB12 in air when heated at a constant rate of 10 °C/min., as well as the results of laser ignition of high-energy materials based on ammonium perchlorate, ammonium nitrate, inert and active combustible binders containing these metal powders. It was found that the use of boron-based powders makes it possible to reduce the temperatures of the onset and intensive oxidation, and to increase their completeness of oxidation in comparison with pure aluminum. The obtained dependences of the ignition delay time on the heat flux density showed that AlB2 and AlB12 powders included in the HEM based on ammonium perchlorate, ammonium nitrate, and an active binder are the most effective metal fuels in terms of reducing the ignition delay time and the heat input.

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Enhanced Thermal Decomposition and Laser Ignition Properties of Nanostructured NC/Al/RDX Composite Fibers Fabricated by Electrospinning

10.21203/rs.3.rs-184430/v1 ◽

2021 ◽

Author(s):

Weimin Wang ◽

Hui Li ◽

Yanjing Yang ◽

Fengqi Zhao ◽

Heng Li ◽

...

Keyword(s):

Thermal Decomposition ◽

Ignition Delay ◽

Delay Time ◽

Ignition Delay Time ◽

High Energy ◽

Decomposition Temperature ◽

High Energy Density ◽

Laser Ignition ◽

Composite Fibers ◽

Combustion Properties

Abstract Nano Al has always been the research hotspot in the field of energetic materials because of its high energy density and combustion temperature, and has been considered as a fuel to enhance the energy release of various propulsive systems. In this work, nanocomposite fibers were fabricated by electrospinning technology, in which nano Al and recrystallized RDX particles were integrated with NC fibers. The morphology and chemical components of NC/Al, NC/RDX, and NC/Al/RDX composite fibers were characterized by XRD, FT-IR, SEM, TEM and BET. The agglomeration of nano Al particles in fibers is significantly inhibited, and the recrystallized RDX and nano Al particles are uniformly dispersed in NC fibers, resulting in the rough surfaces of the composite fibers. The thermal analysis shows that nano NC fibers have lower thermal decomposition temperature (202.1 ℃) and apparent activation energy (149.32 kJ mol-1) than raw NC (208.2 ℃ and 218.5 kJ mol-1), and NC/Al/RDX exhibits improved thermal decomposition properties compared with NC/RDX and NC/Al. The laser ignition experiments suggest that the uniformly dispersed nano Al particles could obviously promote the combustion and shorten ignition delay time. However, RDX may delay ignition due to its high decomposition temperature, but can significantly enhance the combustion properties of NC/Al/RDX fibers. Among the all samples, the NC/Al/RDX (1:1:0.2) exhibits shortest ignition delay time and most violent combustion flames, which can be attributed to the fibrous structure and the enhanced heat and mass transfer between the components.

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Ignition and combustion of high-energy materials containing aluminum, boron and aluminum diboride

MATEC Web of Conferences ◽

10.1051/matecconf/201819401055 ◽

2018 ◽

Vol 194 ◽

pp. 01055

Author(s):

Alexander Korotkikh ◽

Ivan Sorokin ◽

Ekaterina Selikhova

Keyword(s):

Burning Rate ◽

Ignition Delay ◽

Delay Time ◽

Solid Propellant ◽

Ignition Delay Time ◽

High Energy ◽

Solid Propellants ◽

Amorphous Boron ◽

Aluminum Diboride ◽

Ignition And Combustion

Boron and its compounds are among the most promising metal fuel components to be used in solid propellants for solid fuel rocket engine and ramjet engine. Papers studying boron oxidation mostly focus on two areas: oxidation of single particles and powders of boron, as well as boron-containing composite solid propellants. This paper presents the results of an experimental study of the ignition and combustion of the high-energy material samples based on ammonium perchlorate, ammonium nitrate, and an energetic combustible binder. Powders of aluminum, amorphous boron and aluminum diboride, obtained by the SHS method, were used as the metallic fuels. It was found that the use of aluminum diboride in the solid propellant composition makes it possible to reduce the ignition delay time by 1.7–2.2 times and significantly increase the burning rate of the sample (by 4.8 times) as compared to the solid propellant containing aluminum powder. The use of amorphous boron in the solid propellant composition leads to a decrease in the ignition delay time of the sample by a factor of 2.2–2.8 due to high chemical activity and a difference in the oxidation mechanism of boron particles. The burning rate of this sample does not increase significantly.

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NEPE Propellant Ignition and Combustion under Laser Irradiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1042.10 ◽

2014 ◽

Vol 1042 ◽

pp. 10-14 ◽

Cited By ~ 1

Author(s):

Hong Mei Wang ◽

Xiong Chen ◽

Chao Zhao

Keyword(s):

Heat Flux ◽

Laser Irradiation ◽

Ignition Delay ◽

Delay Time ◽

Ignition Delay Time ◽

Flame Temperature ◽

Heat Fluxes ◽

Short Delay ◽

Laser Heat ◽

Nepe Propellant

An experimental study was conducted to get the ignitibility of NEPE propellant under different CO2 laser heat fluxes. The combustion flame temperature distribution of NEPE propellant was measured using an infrared thermometer. Results show that the ignition delay time tends to decrease with the increase of laser heat flux, and there exists a significant value. The ignition delay time decreases fast when the heat flux is less than this value, but varies little when the heat flux is greater than this value. Laser irradiation had a significant effect on the combustion of NEPE propellant and after the laser unloading, the flame temperature of the propellant dose not decline immediately, but fall rapidly after a short delay.

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