Research On Energy Output Characteristics And Influence Mechanism Of Mixed Explosives Containing Composite Hydrogen Storage Materials

One of the technical ways to improve the energy level of mixed explosives is to add hydrogen storage materials,and the research in this area has become a hot spot in the world recently.In this dissertation,the thermodynamic energy release characteristics of Al,B and three metal hydrides（Mg H₂,Ti H₂,Zr H₂）were studied,and the composite hydrogen storage material（AMc）was prepared by optimizing the appropriate ratio and improving the composite process.Then the composite hydrogen storage material was applied to the RDX/AP/hydrogen storage material formula to make the mixed explosive containing composite hydrogen storage materials.The formulation of mixed explosives was optimized by various means.The energy release characteristics of mixed explosive containing composite hydrogen storage materials under water was studied.Meanwhile,the application safety of composite hydrogen storage materials in mixed explosives was improved.The main research contents are as follows:（1）The heat of combustion,ignition energy,and 20 L ball explosion experiments were used to study the thermodynamic energy release characteristics of different materials with high calorific value.The results showed that among the three metal hydrides（Mg H₂,Ti H₂,Zr H₂）,the combustion heat of Mg H₂(29.96 MJ·kg^-1)was 1.43 and 2.45 times that of Ti H₂and Zr H₂,respectively.The minimum ignition energy of Mg H₂（5～10 m J）was much smaller than Ti H₂（150～200 m J）and Zr H₂（250～300 m J）in terms of ignition energy.The maximum explosion pressure and explosion index of Mg H₂were greater than Ti H₂and Zr H₂in dust explosion.Therefore,among the three metal hydrides,Mg H₂was more suitable to be added to the composite hydrogen storage material to improve its thermodynamic energy release.In the mixture of Al,B,and Mg H₂,Mg H₂can effectively increase the combustion ratio of Al and B,and at the same time reduce the ignition energy of the mixture.The content of B was below 20%and the content of Mg H₂was 15%.The mixture showed good thermodynamic properties.The hydrogen storage material（AMc）compounded in an appropriate proportion showed excellent performance in combustion heat,ignition energy and dust explosion power（combustion heat was higher than Al,ignition energy was lower than Al,and dust explosion power was greater than Al）.（2）The detonation heat and underwater explosion were used to study the energy of composite hydrogen storage material explosives with different formulations.The results showed that the detonation heat energy of the composite hydrogen storage material mixed explosive and the underwater explosion energy were better than the aluminum-containing mixed explosive in the same proportion formula.The overall results showed that the RDX（Hexogen）content was 31～36%,the hydrogen storage material content was 35～40%,and the AP（AMmonium perchlorate）content was 20～25%,the composite hydrogen storage material mixed explosive had a higher energy level.The maximum detonation heat was 1.89times TNT（Trinitrotoluene）equivalent,and the total underwater energy（400g）was up to2.21 times TNT equivalent.The composite hydrogen storage material coated with 0.2%BR（cis-polybutadiene rubber）and HTPB（hydroxy-terminated polybutadiene）had basically no effect on the underwater energy characteristics of the mixed explosive,but greatly improved the safety performance during the preparation of the explosive.（3）Research results on energy levels of explosives containing three metal hydrides showed that the laws of the detonation heat and underwater explosion energy of three mixed explosives containing hydrogen storage materials were Mg-based（Mg H₂）>Ti-based（Ti H₂）>>Zr-based（Zr H₂）.Metal hydrides with high activity had a greater impetus for the energy release of hydrogen storage materials in mixed explosives.Zr H₂had poor applicability in the optimized formula system of this article which the explosion heat and underwater explosion energy were both lower than TNT.The scale effect of mixed explosive containing composite hydrogen storage materials in aΦ8.0m×8.0m pool showed that the TNT equivalent results of different samples under different masses were basically the same.However,the calculated result of underwater explosion energy increased with the increase of mass（160g-800g）.Combining boundary effect and mass effect,the TNT equivalent of 400g showed the best results.A two-dimensional mathematical model was established to simulate the underwater explosion process of TNT,aluminum-containing explosives,and mixed explosives containing composite hydrogen storage materials at the same time.The bubble pulsation period calculated by simulation and the test error were maintained within 10%.The underwater explosion characteristic parameters of the mixed explosive containing composite hydrogen storage materials were obtained through the large pool test finally.（4）The large pool test showed that the underwater explosion energy stability of the mixed explosive containing the composite hydrogen storage material was good,and the characteristic parameters of the underwater explosion were obtained through the test.Explosion tests under simulated deep-water environmental conditions showed that the shock wave energy gradually decreases with the depth of the mixed explosive containing composite hydrogen storage materials in the range of 300～600 m.The spherical pressure vessel used in the simulation produces a convergence effect which compressing the bubble pulsation during the bubble pulsation.And the longer the pulsation period,the more obvious the convergence effect.（5）The stability and compatibility of hydrogen storage materials and other components showed that the unit gas production of Mg H₂was larger,with a gas production rate of 5.15 m L·g^-1,while the gas production of Ti H₂compatible with RDX/AP was more than 3.0 m L.Therefore,further treatment of Mg H₂and Ti H₂was needed in the preparation of mixed explosive.The stability and compatibility hydrogen storage materials with Mg H₂or Ti H₂after composite and rubber-coated（cis-polybutadiene and hydroxyl-terminated polybutadiene）meet the requirements.BAM friction and BAM impact sensitivity were used to study the safety performance of mixed explosives containing composite hydrogen storage materials.The results showed that the impact sensitivity（40～45 J）of mixed explosives containing composite hydrogen storage materials is lower than that of RDX（7.5J）,and the friction sensitivity was similar to that of RDX.The mechanical sensitivity of the coated composite hydrogen storage explosive was greatly reduced.