For the optimization and scale-up of the dilution crystallization process of 2,6-dipicrylamino-3,5-dinitropyridine(PYX),the dilution crystallization kinetics of PYX was studied in the crystallization system with DMF as the solvent and H2O as the anti-solvent.Firstly,the solubility curves of PYX in DMF pure solvent and DMF-H2O binary solvent were measured by with laser dynamic method,by which the corresponding solubility models were established.And then,the crystal growth type of PYX was determined.The crystal growth and nucleation rates of PYX in the dilution crystallization process were measured,and the corresponding crystallization kinetics models were established.On this basis,the effect factors and laws of the crystalliza-tion kinetics of PYX were analyzed.The results show that the solubility of PYX in DMF pure solvent and DMF-H2O binary sol-vent with different volume ratios increases with increasing temperature,and decreases with increasing H2O content.The solu-bility of PYX in different solvents was fitted by Apelblat model,where the correlation coefficients of the fitting results are all greater than 0.99.The crystal growth type of PYX is particle size independent growth.The crystal growth and nucleation acti-vation energy of PYX are 8.33 × 103J/mol and 1.01 × 104J/mol,respectively.The index of supersaturation ratio to crystal growth rate is 6.73.The stirring strength,supersaturation ratio and suspension density to crystal nucleation rate are 0.27,7.16 and 0.14,respectively.The crystal growth and nucleation rates of PYX increase along with the increase of temperature and supersaturation ratio.Also,the increase of temperature or supersaturation ratio is more conducive to the crystal nucleation of PYX.Compared with the supersaturation ratio,the stirring intensity and suspension density have less effect on the crystal nu-cleation rate of PYX,and increasing the stirring intensity or suspension density is detrimental to the crystal growth of PYX.

In order to optimize the crystal formability and improve the application performance of PYX, the solvent-antisolvent method was used to recrystallize PYX, and the better recrystallization system was determined. The influencing factors and laws of PYX crystal morphology and particle size distribution were explored, and the recrystallization conditions were optimized. The crystal structure, thermal property and mechanical sensitivity of PYX before and after recrystallization were analyzed. The results show that using 1-methyl-2-pyrrolidone（NMP） as solvent and water as antisolvent, the regular cubic crystals can be prepared under the conditions: crystallization temperature is 65℃, stirring rate is 300r/min, crystallization concentration is 20mg/mL, and antisolvent adding rate is 2mL/min. The crystal length-diameter ratio is significantly smaller than those before recrystallization, and has no obvious defects, and with good surface smoothness. Recrystallization can reduce the average particle size and optimize the uniformity of particle size distribution of PYX. The particle size(d 50 ) and the particle size span（S） of PYX after recrystallization is reduced by 49.51μm and 0.27 compared with that before recrystallization, respectively. The crystal structure of PYX does not change after recrystallization. Recrystallization can improve the thermal stability of PYX and reduce the mechanical sensitivity of PYX. After recrystallization, the thermal decomposition peak temperature and thermal explosion critical temperature of PYX are increased by 5.0℃ and 6.6℃, and the impact sensitivity and friction sensitivity are decreased by 20% and 16%, respectively.

分别采用降温法和溶剂-反溶剂法对2,6-二苦氨基-3,5-二硝基吡啶(PYX)进行了重结晶研究.表征了不同重结晶方法所得PYX晶体的形貌和粒径,测定了重结晶前、后的晶体纯度,研究了重结晶对晶体热性能和机械感度的影响.结果表明:采用降温法在DMSO中得到的多为小颗粒团聚形成的不规则块状PYX晶体;采用溶剂-反溶剂法在DMF或DMSO中得到的多为片状PYX晶体,在DMSO/DMF混合溶剂中得到的多为规则的多边形块状PYX晶体.相比较而言,多边形块状PYX晶体的表面光滑度良好,粒径跨度最小,纯度最高,热稳定性较优,且兼具最低的撞击感度和摩擦感度,其热分解峰温和热爆炸临界温度较重结晶前分别提高了8.99℃和9.11℃,撞击感度和摩擦感度较重结晶前分别降低了16％和12％.

为了研究HMX基含铝炸药的冲击起爆特性,对其进行了两种加载压力下的冲击起爆试验.结果表明,加载压力为14.68 GPa时,其到爆轰距离为12.04～15.38 mm;加载压力为15.55 GPa时,到爆轰距离为10.23～12.01 mm;稳定爆轰后的爆轰压力约为25 GPa.基于圆筒试验确定了HMX基含铝炸药的JWL状态方程参数,结合两种加载压力下的冲击起爆试验结果进行数值模拟,标定并验证了点火增长模型反应速率方程参数.计算结果与试验结果一致.得到14.68 GPa加载压力下HMX基含铝炸药到爆轰时间为2.5μs,到爆轰距离为13.70 mm;15.55 GPa加载压力下的到爆轰时间为1.9μs,到爆轰距离为10.60 mm.计算结果表明,加载压力增大,前导冲击波速度增长变快,波阵面压力增长变快,炸药到爆轰时间与到爆轰距离减小,爆轰成长阶段同一时刻下的波阵面压力增长速率也随之增大.

为了得到等离子体起爆电压及等离子体与不敏感含能材料接触面积对起爆响应强度的影响规律,选择典型分子类不敏感含能材料FOX-7、LLM-105和TATB,以及离子类不敏感含能材料FOX-12和HATO,以金属丝电爆炸为等离子体源,进行15、20和25 kV起爆电压及直线形(Z)和螺线形(W)金属丝形状的等离子体起爆试验,以见证板形貌及最大形变量判定含能材料的爆轰响应强度.结果表明,不同种类含能材料对等离子体的起爆响应不同,增加等离子体起爆电压可以显著增加分子类不敏感含能材料FOX-7、LLM-105和TATB的响应强度,其响应强度顺序为W/25 kV>Z/20 kV>W/20 kV;而离子类不敏感含能材料FOX-12和HATO对等离子体起爆条件没有显著规律;分子类不敏感含能材料比离子类不敏感含能材料对等离子体起爆电压和等离子体与含能材料的接触面积更敏感.

以某改性单基发射药为研究对象,采用聚焦微波消解法,将试样消解为试样溶液,以火焰原子吸收法测定其中的钾元素含量,结果表明,钾元素的平均回收率为104.3％(n=7),相对标准偏差(RSD)为3.47％(n=7),其测定结果与传统电热板消解法无显著性差异,消解时间缩短1h.

通过卤素水分测定仪和烘箱法测定了硝化棉的水分含量,研究了影响卤素水分测定仪测定硝化棉水分含量的因素,并与传统烘箱法进行了对比.结果表明,干燥温度、干燥时间对卤素水分测定仪测定硝化棉水分含量影响较小,样品质量、质量损失率是影响卤素水分测定仪测定硝化棉水分的重要因素;卤素水分测定仪测试结果与烘箱法结果基本一致,测量结果重复性好,试验相对标准偏差小,极大的缩短了检测时间,可以用于实际生产中的质量控制.

为了研究氧化剂高氯酸铵(AP)对RDX基含铝炸药爆轰性能的影响,利用含铝复合炸药的金属飞片加速试验和冲击起爆试验,结合含铝复合炸药的爆炸参数,分析了RDX基含AP复合炸药和RDX基无AP含铝炸药的爆轰性能.金属飞片加速试验表明,与后者相比,RDX基含AP复合炸药由于较低的爆炸反应速率,金属加速能力降低约11.5％.冲击起爆试验表明,RDX基含AP复合炸药的爆轰距离较长,在23.72～34.00 mm范围爆轰持续稳定,并且能保持较长时间的稳定爆轰.

To estimate the deflagration to detonation transition (DDT) process of explosives composed of common components,three kinds of composite explosives,P1 (40 ％ TNT/60 ％ RDX),P2 (40 ％ DNTF/40 ％ HMX/10 ％ TATB/5 ％Al/5 ％additives) and P3 (25 ％DNTF/40 ％AP/30 ％Al/5 ％additives) were prepared by melting-casting technology,and explosive P4(30 ％RDX/30 ％ AP/30 ％ Al/10 ％additives)was prepared by casting technology.The DDT test for the four kinds of explosives were carried out by the coaxial ionization probe test technology,and the DDT response characteristics of four kinds of explosives were analyzed by the broken status of DDT tube,wave front propagation velocity in the DDT process and detonation transition distance.The results show that the DDT of explosives P1,P2 and P3 takes place and the detonation transition distance is 750-825 mm,375-450 mm and 675-750 mm,respectively,while the DDT of explosive P4 does not take place.For the brokenness of DDT tube,explosive P2 is the most violent,explosive P3 is second and explosive P1 is the smallest,indicating that the broken extent of DDT tube is positive correlation to the detonation pressure of explosive and if the formulation contains the ingredients that the thermal decomposition temperature is approaching,the thermal decomposition energy can be added quickly,and causes the combustion to be unstable,then increases DDT.The casting technology can decrease the possibility of DDT due to the presence of inert additives on the isolation coating and absorption action of explosive components.

In order to research the effect of contents and particle sizes of Al powder on the air blast property of explosive, over-pressure, pressing time and impulse of aluminized explosives with different formula were tested and com-pared in this article.The result shows that explosive containing Al at the range of 30%-35%( mass fraction) has higher over-pressure and impulse than other explosive.With the increase of Al content (mass fraction is higher than 35%), over-pressure and impulse decrease.Free-field sensor shows that explosive containing 30%Al (mass fraction) gives rise to the highest over-pressure and impulse values in 4.5 m distance.Moreover explosive containing 30% nano-Al (mass fraction) has lower over-pressure and impulse than explosive containing micro-Al.

In order to improve the detonation energy of explosive, based on the factors affecting boron-reactivity in explosion, through selecting particle size and purity, adding reactive metal, preparing hydrogen-alloy containing boron, using fluorine-binder, the boron-oxidation and reactivity during explosion was improved. The under-water explosion results show that, detonation energy output of boron-explosive can be effectively increased by above ways.

To study the effective regulation and control technology of the deflagration to detonation transition (DDT) process for DNTF-based composite explosive,the effect of ignition charge mass,DDT tube wall thickness constraint and molding way etc.on the performance of DDT for DNTF-based composite explosive was investigated by the coaxial ionization probe test technology.The test results were analyzed from the view of the change in rupture state of DDT tube,wave front velocity at different location of DDT process and inducement detonation distance etc.Results show that the DDT tube wall thickness constraint has no significant effect on the inducement detonation distance of DDT for DNTF-based composite explosive,which is at about 375 mm,but decreasing wall thickness can make the duration time of deflagration stage increase and the initial velocity to detonation reduce to 551 5 m · s-1.Increasing ignition charge mass has no significant effect on the reaction violence of DDT for DNTF-based composite explosive,but it can reduce the duration time of initial combustion and detonation induced distance.The duration time of initial combustion,duration time of deflagration and detonation induced distance of the pressed molding specimen are greater than those of the cast specimen,but there is no obvious difference in the violence of the reaction.

The process and characteristics of deflagration-to-detonation transition(DDT)in high density and shaped explosives were analyzed.The effect of desensitizer and two charging methodology which involves melt cast-ing and press loading on DDT were considered by means of electrical pins.The detonation-induced distances in dif-ferent conditions were also compared.The results show that detonation is induced by shock waves deriving from the accumulation of combustion compression waves,which is the primary mechanism for the DDT in high density and shaped explosives.The detonation-induced distance would be longer when desensitizer was added in explosives,be-cause the desensitizer has big heat capacity and small thermal conductivity.The melt casting explosive is easier to be crushed which will increase the burning area and combustion speed,as the compression strength of melt casting explosive is lower and crisper than press loading explosive.The melt casting explosive tends to reduce detonation-induced distance.

提出了采用反相高效液相色谱法测定含RDX的叠氮硝胺发射药中RDX、硝化甘油(NG)、1,5-二叠氮基-3-硝基氮杂戊烷(DIANP)和中定剂(C2)4种组分含量的新方法;试样用丙酮溶剂溶解后进行色谱分离,采用AgilentC18色谱柱(5μm,4.6mm×150mm),以乙腈和水(体积比为65∶35)为流动相,在波长210 nm处进行4种组分含量的测定.结果 表明,在优化的色谱条件下,NG在质量浓度0.02～1.38 g/L,RDX在质量浓度0.02～1.11g/L,DIANP在质量浓度0.02～0.98g/L,C2在质量浓度0.002～0.12g/L时,含量分别与其峰面积呈线性关系;4种化合物的加标回收率在98.4 ％～100.6％,相对标准偏差RSD在0.53％～1.20％.表明该方法准确可靠,可用于含RDX的叠氮硝胺发射药组分含量的测定.

To study the effect of recrystallization process on fhe thermal properties and mechanical sensitivity of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate(HATO, TKX-50), Six kinds of HATO samples with different particle size and morphology were prepared using falling temperature method and solvent-nonsolvent method respectively.The particle size and morphology of HATO samples obtained by different recrystallization process were characterized by laser granularity instrument and scanning electron microscope(SEM).The thermal decomposition properties was analyzed by means of differential scanning calorimeter(DSC).Its impact and friction sensitivities were were measured by GJB772A-97 method.The results show that HATO samples without addition of surfactnt obtained by falling temperature method have maximum particle sizes(d50=196.5 μm), the crystal surface is smooth and the shape is regular, showing the highest decomposition temperature and the lowest mechanical sensitivity.Its decomposition peak is 249.1 ℃.The impact and friction sensitivities are 8% and 20% respectively.

In order to investigate the influence of nano-aluminum on the detonation energy of explosive, RDX-based explosive containing nano-aluminum and micron aluminum were prepared and used in the under-water detonation experiment. Shockwave energy and bubble energy of explosives with different components of nano-aluminum and micron aluminum were measured. Effect of nano-aluminum content on the energy output in under-water detonation was also analyzed. It can be found that shockwave energy and bubble energy of explosives containing 20%-40% ( mass fraction) nano-aluminum are lower than those of explosives containing 20%-40% ( mass fraction ) micron aluminum, and the difference increases with the raise of aluminum content. When the mass fraction of aluminum powder is 30% or 35%, explosives with the mixtures of nano-aluminum and micron aluminum have higher total energy in underwater detonation, and the optimal mass fraction of nano-aluminum is 10%. Results also show that when the mass fraction of aluminum powder is 35% [m (micron aluminum)︰m (nano-aluminum) = 25︰10], underwater detonation energy of the explosive is the highest.

The strain change in the curing process of casting polymer bonded explosives (PBX) containing HTPB was measured by a self-designed device and method. The curing stresses of casting PBX were calculated and the effect of binder with different relative molecular mass on the curing stresses of casting PBX was studied. The bonding strength of casting PBX under different solidification temperature was also tested. Results show that the maximum curing stresses and the shrinkage stresses of PBX decrease with the increasing of relative molecular mass of HTPB under the same curing tem-perature at isothermal curing stage. When the relative molecular mass of HTPB are 1 500, 2 800, 4 000 and the solidi-fication temperature is 100℃, the maximum curing stresses of PBX are 2. 14, 1. 12, and 1. 01 MPa, and the shrinkage stresses of PBX are 0. 29, 0. 22, and 0. 15 MPa. At cooling stage, the shrinkage stresses of PBX increases with an increase in relative molecular mass of HTPB. For the PBX with same relative molecular mass of HTPB, the binding strength decreases with the increase of solidification temperature, while the relative molecular mass of HTPB has little effect on the binding strength of PBX.

The low-speed impact loading of the charge JO-8 and composition B were researched by the small hammer, the course and the tested sample were analyzed by the high speed photography and SEM respectively. The impact experiment found that the charge JO-8 has much higher anti-impact ability than composition B, the two charges were found to experienced the course of shocking, plastic flowing, flying and reacting through the high speed photography, and the reaction happened after damage. The SEM found that the damage pattern of composition B was focused on the interface debond and rupture across the crystal, and JO-8 was focused on the shear distort and rupture through the crystal. The research suggested that the binder can improve the anti-impact ability of the charge, the damage pattern was depended on the charge techniques.

采用30 kg小落锤对JO-8和B炸药进行了低速撞击加载试验,并对撞击过程和试验后样品分别进行了高速摄影和扫描电镜分析.撞击试验发现JO-8炸药的临界点火阈值为360 N,B炸药的阈值为300 N,这表明JO-8炸药具有更高的抗撞击能力;高速摄影发现两种炸药均经历冲击、塑性流动、飞散、反应等阶段,反应在炸药损伤后发生,JO-8炸药的反应滞后于B炸药;扫描电镜表明,B炸药在低速撞击下的损伤模式以界面脱粘、沿晶断裂为主,JO-8炸药以剪切变形和穿晶断裂为主.B炸药的制备工艺决定了TNT包裹RDX的微观结构,而TNT具有较低的晶体力学性能,导致其在加载下首先发生断裂;JO-8炸药的制备工艺决定了粘结剂包裹HMX晶体的微观结构,粘结剂改善了炸药晶体的脆性特征,致使JO-8炸的损伤模式不同;与B炸药相比,JO-8炸药发生点火延滞的原因在于JO-8炸药具有更高的压缩强度.

In order to study the safety of explosive columns under low speed impacting multiple stimulations,the multiple environments test system was established and the low-impact sensitivity tests of Composite B and JO8 were carried out under the temperature of- 40 ℃,20 ℃ and 70 ℃. The density of CO,CO2 and H2in the impacting hermetic room were monitored by the gas-sensitive detection system to determine the status of the columns explosion,which improves the accuracy of the judgment of explosion. The critical drop height of Composite B and JO8 under three different temperatures was obtained. The results show that the critical drop height has no very direct relationship with temperature. The impacting safety of Composite B and JO8 is not sensitive to temperature in a certain temperature range from 20 ℃ to 70 ℃. Under an environment with lower temperature,the Composite B is slightly insensitive and JO8 tends to be more sensitive.