Energy Performance and Aging of RDX‐based TiH₂, MgH₂ Explosive Composites

Abstract

Two typical binary metal hydrides, TiH2 and MgH2 were introduced into the RDX based explosive composites. Charges with different contents of metal hydride were evaluated through underwater explosion. Composite with 10 % MgH2 exhibited the best shockwave parameters, peak overpressure, specific impulse and specific shock energy of which promoted by 5.7 %, 7.0 % and 8.4 % respectively. Whereas, the specific bubble energy of composite with 10 % TiH2 showed the maximum enhancement of 5.5 %, and density specific energy of which increased significantly attributed to the large density of TiH2. Meanwhile, a 2‐year ambient storage test of metal hydride reactants and RDX‐metal hydride explosive composites was conducted to evaluate the safety and stability. X‐ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA) were then conducted to analyze the aged samples. Results revealed that TiH2 and its explosive composites showed an excellent storage stability due to the formation of thin TiO2 film. Whereas, mass fraction of Mg(OH)2 was found increasing with time in both MgH2 and its explosive composite, of which hydrolysis of MgH2 was the main mechanism. Moreover, Mg was found in aged MgH2 powder as a result of decomposition. The mechanical strength of aged charges of RDX based MgH2 explosive composite also degraded significantly ascribed to the released hydrogen.

Thermal Decomposition Mechanism of 1,3,5,7-Tetranitro-1,3,5,7-tetrazocane Accelerated by Nano-Aluminum Hydride (AlH3): ReaxFF-Lg Molecular Dynamics Simulation

“…However, some studies have found that metal hydrides can replace metals as better additives to mix with EMs. 6,7 Compared with metal power, metal hydrides possess high hydrogen storage capacity and higher combustion heat. Their decomposition can release large amounts of hydrogen, which allows them to release more energy and decline the average molecular weight of the gas in the combustion process.…”

“…Research shows that EMs with high active metal additives have higher detonation and combustion properties. − Commonly used high active metal additives include aluminum, magnesium, boron, and so forth. However, some studies have found that metal hydrides can replace metals as better additives to mix with EMs. , Compared with metal power, metal hydrides possess high hydrogen storage capacity and higher combustion heat. Their decomposition can release large amounts of hydrogen, which allows them to release more energy and decline the average molecular weight of the gas in the combustion process. , Common metal hydrides include MgH 2 , CaH 2 , AlH 3 , and so forth.…”

Detonation Characteristics of an Aluminized Explosive Added with Boron and Magnesium Hydride

“…The addition of metal hydride materials into explosives has also been investigated by many researchers recently. For instance, the detonation properties of ammonium nitrate (AN)/RDX/TNT with AlH 3 /MgH 2 [11], the explosion properties of RDX with MgH 2 /TiH 2 [12][13][14] and emulsion explosives with MgH 2 /TiH 2 [15][16][17], the detonation heat and confined explosion parameters of RDX with TiH 2 /ZrH 2 [18,19], the mechanical sensitivity of AN/TNT/RDX with MgH 2 /Mg(BH 4 ) 2 [20], and the thermal behaviors of TNT with MgH 2 /Mg(BH 4 ) 2 [21] and TNT/RDX with Mg(BH 4 ) 2 [22] were reported. The objective of the present work is to determine the detonation characteristics of a novel aluminized explosive added with B and MgH 2 to explore what role of B and MgH 2 play in the detonation reaction.…”

Effect of Magnesium Stearate Coating on Degradation of NH4ClO4/Mg by Moisture

“…Degradation of various compositions by moisture persists as one of the serious problems in the field of energetic materials [1][2][3][4][5][6][7][8]. In particular, pyrotechnic compositions containing magnesium (Mg) powder are degraded easily by water [9].…”