Research on Detonation Growth of Lead Azide (Pb(N₃)₂) Microcharge

Abstract

Microelectromechanical system (MEMS) fuzes are an important development for detonator miniaturization, leading to devices often used as input for an explosive train. The output capability of a microdetonator is strongly influenced by detonation growth of the primary explosive. In this article, research made use of a manganin piezoresistance measuring method to investigate the detonation growth properties of charges of lead azide (Pb(N 3 ) 2 ) at micrometer diameters and density of 80% theoretical mean density (TMD). The samples developed for this research were cylindrical charges of lead azide contained in stainless steel capsules 0.9 mm in diameter and 3 mm in height. An electrical igniter was applied to ignite the charges. The fitting curve for detonation pressure versus height of the explosive charge was obtained, revealing that the critical height of the detonation growth in the microcharge was 1.8 mm, and the detonation growth was stable at the height of the charge at 2.4 mm. The maximum detonation pressure achieved was 6.0 GPa.

Study on microcharge design and output performance test

“…Among them, microcharge is the energy source of MEMS pyrotechnics. The performance of microcharge directly determines the performance of MEMS pyrotechnics [2][3][7][8]. The characteristic size of microcharge of MEMS pyrotechnics is generally tens of microns to 1mm, which is lower than the critical size of stable fire transmission and explosion transmission of conventional fireworks, and typical non-ideal characteristics are presented in micro-size detonation [9].…”

“…The study of charging method shows that the precision pressing technology is only suitable for charging above millimeter scale. Although in-situ self-assembly, vacuum charging and other forming technologies can obtain sub-millimeter size charge, the molding density is low (65% TMD) and the explosion capacity is poor [7][8][9]. Common charging processes are no longer suitable for MEMS pyrotechnic charging.…”

Pressure Measurements of Aluminized Explosives Detonation Front with Different Aluminum Particle Size

“…Pressure is one important thermodynamic characteristics of explosive detonation, which can provide the reaction of aluminum with detonation products. Manganin piezoresistance gauge has been used to measure pressure of a decade years, which can be saw in many papers [6,7]. In this paper, detonation pressure of aluminized explosive with different particle size is measured by manganin piezoresistance gauge to determine the reaction of aluminum with detonation gas.…”

Tests and Simulation Research on the Output Energy of Microdetonators

“…Use of a charge amplifier affects output pressure tests on small initiating explosive devices. Yan et al [10] designed a micro-Manganin gauge to investigate the output capability of a lead azide microdetonator and used the Manganin piezoresistance method to measure the relationship between detonation pressure growth and the height of a Pb(N 3 ) 2 microcharge. They successfully measured the output detonation pressure for a microcharge.…”