Effect Of Mg(BH₄)₂ On The Mechanical Sensitivity And Energy Output Characteristicsof RDX-based Explosives

As a hydrogen storage material,Mg(BH4)2 is favored because of its high heat value and low hydrogen release temperature.However,the safety of explosives in the process of preparation and transportation is also an important indicator of the value of explosives.There are reports in the literature that the introduction of Mg(BH4)2 into energetic materials is difficult to achieve application value due to the high mechanical sensitivity.In order to reduce the mechanical sensitivity of mixed explosives containing Mg(BH4)2,this article uses D-RDX as the main explosive,adding a certain proportion of Mg(BH4)2,Al powder,AP and the process of preparing molding powder(PMP)was adopted.Paraffin as insensitive agent,cis-polybutadiene as a binder to cover the main explosive D-RDX.A constant temperature detonation calorimeter and an oxygen bomb calorimeter were used to test the detonation and combustion heat of the explosive.The underwater explosion method was used to test the shock wave parameters and bubble pulsation of the underwater explosion to explore the energy output characteristics of the mixed explosive.Explosive mechanical sensitivity is analyzed.The results show that the size of the explosive particles is significantly increased(average particle size from 136 microns to 365 microns)and the particle sizes are similar by using the process of preparing modeling powder.This process increases the characteristic drop height of the coated explosive from 17.8cm to 75 cm,and reduces the probability of frictional explosion from 100% to 36%,which greatly reduces the mechanical sensitivity of the explosive and improves the transport and performance of the explosive.Security during storage.The explosive heat test results show that the explosive heat of the coated explosive is lower than the original,but it is 6% higher than that of the D-RDX.This shows that by adopting the process of preparing molding powder,not only can the mechanical sensitivity of explosives containing Mg(BH4)2 be greatly reduced to meet safety requirements,but also the explosive heat can be increased by 6% on the basis of D-RDX,which makes high energy storage The application value of hydrogen material Mg(BH4)2 in the field of energetic materials is reflected.However,for mixed explosive formulations containing both Mg(BH4)2,Al and AP,the total explosive detonation heat and underwater explosion energy decrease with the increase of Mg(BH4)2 content,the combustion heat gradually increases but the combustion efficiency is downward trend.This is because the addition of Mg(BH4)2 changes the explosive reaction mechanism of explosives,making the negative oxygen balance of the explosive system more serious.However,due to its strong after-burning effect,the addition of Al powder makes the Mg(BH4)2 incomplete.The combustion phenomenon is alleviated,and the energy of the entire system is greatly improved.After adding AP,the detonation heat of the explosive system is improved,which shows that AP plays an important role in improving the oxygen balance of Mg(BH4)2 mixed explosives.