NC基高能低敏感发射药的低温抗冲击强度

为研究NC基高能低敏感发射药的低温力学性能,通过改变配方中硝化棉(NC)的种类、增塑剂ZSJ-X的含量、FOX-7的含量以及RDX和FOX-7的粒度,制备了4种NC基高能低敏感发射药,采用电子万能材料试验机测试了其低温抗冲击强度。结果表明,降低黏结剂的含氮量,增加增塑剂ZSJ-X的含量,用FOX-7替代部分RDX,降低RDX和FOX-7的粒度,能够提高NC基高能低敏感发射药的低温抗冲击强度。当NC基高能低敏感发射药的配方(质量分数)为:NC(含氮量12.6%)37%、ZSJ-X 25%、FOX-7(粒径19μm)13%、RDX(粒径5μm)33%时,低温抗冲击强度最佳,达到7.75kJ/m2。     

少烟NEPE推进剂的表面和界面性能

根据表面和界面化学原理,应用动态接触角测量仪和表面-界而张力仪测试了少烟NEPE推进剂的黏合剂体系(PNT)、填料(HMX、AP和Al粉)和键合剂的表面和界面性能.结果表明,填料(HMX、AP和Al粉)与黏合剂体系(PNT)的界面张力(γsl)大小顺序为:γAl/PNT＜γAP/PNT＜γHMX/PNT,填料与黏合剂体系的黏附功(Wa)大小顺序为:Wa(Al/PNT)＞Wa(HMX/PNT)＞Wa(AP/PNT);键合剂能够自发吸附和分散在推进剂的填料(HMX、AP和Al粉)表面和黏合剂体系中;在推进剂制备过程中,键合剂吸附于填料表面形成的界面能够稳定保持在黏合剂体系中;键合剂能明显提高推进剂的强度和模量,改善填料颗粒与黏合剂体系的界面粘结性能,这与表面性能测试结果一致.     

端环氧聚丁二烯与固体填料之间表界面性能的研究

为了解推进剂中黏合剂与固体填料之间的界面性能,以端环氧聚丁二烯(ETHTPB)为黏合剂,以Al(铝粉)、AP(高氯酸铵)、RDX(黑索金)和HMX(奥克托金)为填料,采用动态接触角测量仪和界面张力仪对黏合剂与固体填料之间的性能(如接触角、表面张力、界面张力、黏附功和铺展系数等)进行了表征和计算。研究结果表明:ETHTPB的表面张力较小,在固体推进剂组分表面易铺展;ETHTPB与固体填料之间的黏附功大小依次为Wa(ETHTPB-AP)Wa(ETHTPB-RDX)Wa(ETHTPB-HMX)Wa(ETHTPB-Al),ETHTPB与固体填料之间的铺展系数大小依次为SSL(ETHTPB-AP)SSL(ETHTPB-RDX)SSL(ETHTPB-HMX)SSL(ETHTPB-Al)。     

不同粒度RDX对DAGR发射药试样抗冲击性能的影响

为了研究黑索金(RDX)粒度对DAGR高能硝胺发射药抗冲击性能的影响规律,以DAGR药片为原料,分别加入用Tyler标准筛筛分的6种不同粒度的RDX,制备成相同RDX含量的试样,通过落锤冲击试验和摆锤冲击试验分别对所制备的发射药试样进行了轴向和径向抗冲击性能测试。研究结果表明,随着RDX粒度的减小,发射药试样的抗冲击性能逐渐增加。通过对试样冲击断面进行亚微观形貌观测,发现试样断裂面中固体填料RDX颗粒与粘结剂基体之间存在相互剥离的现象,断裂面上存在裸露的RDX颗粒及RDX与基体剥离所形成的空穴。     

RDX粒度对改性单基药燃烧性能及力学性能的影响

为了研究RDX粒度对改性单基药性能的影响,采用溶剂法挤压成型工艺,制备了含不同粒径(0.5、7.6和100μm)RDX的改性单基药;通过密闭爆发器试验测试了改性单基药的燃烧性能;采用万能材料试验机、简支梁式抗冲击试验机测试了改性单基药的力学性能;并通过扫描电镜观察了冲击断面,分析了改性单基药的破坏机理。结果表明,当RDX质量分数为10%时,改性单基药的燃速随着RDX粒度的增大而增大;小粒径RDX(0.5与7.6μm)改性单基药燃烧稳定,当RDX粒径增至100μm时,改性单基药在60MPa附近的u-p曲线出现转折,燃速压力指数突变,燃烧不稳定;改性单基药的抗压强度与抗冲击强度随着RDX粒度的增大而降低;RDX粒度显著影响发射药样品的断裂模式;当RDX粒度较小时,改性单基药的抗冲击强度主要受RDX颗粒与NC基体的界面黏结强度影响;当RDX粒度增大后,单基药的抗冲击强度主要受RDX颗粒的自身强度和其与NC基体的界面黏结强度共同影响。     

不同含氮量的NC低分子溶液体系小分子扩散性能研究

研究了含氮量在11．2％－13．6％范围的硝化棉（NC）和三醋酸甘油酯体系溶解及分子扩散动力学过程。重点研究了含氮量较均匀的中氮量（12．2％）NC的分子量分布及结晶度对扩散性能的影响。建立了NC浓溶液区试样结晶度与扩散系数、稀溶液区扩散系数与NC平均分子量间关系。     

RDX和HMX单晶的压痕断裂韧性

使用纳米压痕仪在HMX、RDX单晶表面进行压痕实验,并用不同压痕方程计算了单晶的断裂韧性.计算得到HMX晶体(010)面与RDX晶体(020)、(210)面间断裂韧性分别力0.092543、0.097387、0.10072 MPa·m1/2.结果表明,实验单晶的KIC值遵循Palmqvist系裂纹系统shetty方程,...     

热红联用研究AP与RDX和HMX混合体系的热分解

用DSC-TG-FTIR(热红)联用研究了RDX/AP,HMX/AP,RDX/HMX和RDX/HMX/AP混合体系的热分解,测定和比较了它们的热分析特征量和分解气相产物.结果表明,AP与RDX和HMX之间存在强烈的相互作用,尤其是与后者的作用更强烈.在AP(不含碳)分解的温度区间,混合体系的分解也出现CO、CO2和CH2O等碳氧化物,说明体系中RDX和HMX分解的部分产物或残渣与AP同时分解.     

纳米铝粉对硝胺炸药热分解催化性能的影响

采用直流电弧等离子体蒸发法制备了高纯度的纳米铝粉,并用比表面积分析仪和扫描电子显微镜(SEM)对样品进行了表征.将纳米铝粉与硝胺炸药HMX和RDX用研磨混合法制成混合粒子,用DSC对单质HMX和RDX炸药以及纳米铝粉/硝胺炸药混合物进行催化特性测试,并对样品的热分解动力学和热力学参数进行了计算和对比.结果表明,加入纳米铝粉后,HMX和RDX在不同升温速率(2、5、10、20 K/min)下的放热峰峰温降低,活化能分别降低15和16 kJ/mol,热力学参数都有明显变化.纳米铝粉对HMX和RDX有明显的热分解催化作用.     

硝化工艺及原料的预处理对硝化棉含氮量及其分布均匀性的影响

采用硝化棉(NC)含氮量及其分布均匀性测试仪,考察了硝化系数、精制棉的膨润预处理和超声预处理三因素对硝化棉含氮量及氮量分布均匀性的影响规律.结果表明,NC的含氮量随硝化系数的增大而增大.当硝化系数分别为40、50和80时,NC含氮量分布值Dε较小,当硝化系数为20或100时,Dε值均显著增大;采用硫脲和尿素水溶液预处理...     

Preparation and Properties of a nRDX‐based Propellant

The incorporation of nano‐scaled cyclotrimethylene trinitramine (nRDX) in nitrocellulose (NC)‐based propellants poses processing problems when following conventional methods. Hence, a new preparation method containing a pre‐dispersion process was developed, by which 30 mass % RDX (290 nm) was incorporated in the propellant. Meanwhile, the corresponding 290 nm, 12.85 μm and 97.76 μm RDX‐based propellants were prepared for comparison using a conventional method. The morphology, structure, ballistic and mechanical properties of the prepared propellants were characterized by scanning electron microscopy (SEM), density analyzer, closed vessel (CV), uniaxial tensile tester and impact tester. The results indicate that the nRDX particles were uniformly dispersed in the NC/NG/TEGDN matrix using the novel method, while agglomerated and recrystallized into large particles with the conventional method. The propellant density increased with decreasing RDX particle size. In particular, the 290 nm RDX‐based propellant exhibited a higher burning rate and lower average pressure exponent (α =0.958) compared to the 12.85 μm RDX‐based propellant (α =1.043). The tensile strength, elongation at break and impact strength of the RDX‐based propellant at −40 °C, 20 °C and 50 °C were dramatically improved by using 290 nm RDX with the novel method.     

还原型锡酸铅粒度对Al/HMX/CMDB推进剂燃烧性能及安定性的影响

为研究还原型锡酸铅粒度对Al/HMX/CMDB推进剂燃烧性能及安定性的影响,采用干筛法筛选6种不同粒度的还原型锡酸铅,制备了含不同粒度还原型锡酸铅体系的推进剂;通过燃速靶线试验、甲基紫试验与热加速老化试验得到推进剂的燃速、压强指数、甲基紫变色时间和贮存寿命。结果表明,随还原型锡酸铅粒径由7.0μm减至2.5μm,Pb²⁺及SnO₂的催化活性逐渐增大,活化中心愈多,该体系推进剂在15~20MPa范围内的燃速逐渐增加,压强指数由0.30减至0.17;同时还原型锡酸铅粒度的减小加速了该体系推进剂的自催化作用,造成其安定性下降,当还原型锡酸铅的粒径为2.5~3.5μm时,推进剂的安定性显著降低。     

Application of Nitramines Coated with Nitrocellulose in Minimum Signature Isocyanate‐Cured Propellants

Cyclotrimethylenetrinitramine (RDX) coated with nitrocellulose (NC‐RDX) is prepared by an internal solution method and applied in a minimum signature isocyanate‐cured propellant. It was found that RDX was coated or bonded by NC to form NC‐RDX particles; the median particle diameter (d₅₀) and specific surface area of NC‐RDX are in the range from 150 to 240 μm and 0.03 to 0.04 m²⋅g⁻¹, respectively. The NC‐RDX particles could swell in nitrate ester plasticizers with relatively low swelling rate compared with NC added directly in the plasticizers. Different types of ballistic modifiers can be effectively added to NC‐RDX. It was experimentally shown that NC‐RDX can increase the content of NC in the propellant with viscosities in the range from 371 to 394 Pa s and improve the mechanical characteristics of the propellant with maximum tensile strength (σ_m) between 0.48 MPa<σ_m<1.92 MPa, elongation at maximum tensile strength (ε_m) between 28.0%<ε_m<37.3%, and elastic modulus between 3.18 MPa<E<8.68 MPa in the temperature range from −40 to +50 °C.     

超细HMX的表面能研究

用DCAT21型表面/界面张力仪测量了原料HMX（奥克托今,45μm～62μm）、超细HMX（0.2μm～1.7μm）和黏结剂FPM2602的接触角,并计算出它们的表面能。分析了HMX随粒径变化时其表面能的变化规律和黏结剂包覆超细HMX表面能的基本要求。结果表明,细化HMX表面能随粒径的减小有增加的趋势;黏结剂的表面能低于超细HMX的表面能,理论和实验均证明黏结剂FPM2602能包覆于超细HMX的表面。     

Effect of RDX and HMX on the Efficiency of Catalysts for Double–Base Propellant Combustion

High explosives (RDX or HMX) are added to double–base propellant formulations to improve their energy characteristics. The influence of these HE on the catalysis of propellant combustion practically has not been discussed in the literature. The present paper considers the role of RDX and HMX in the catalysis of double–base propellant combustion. Propellants having various compositions and energy characteristics were studied experimentally. It is established that RDX and HMX decrease the burning rate of double–base propellants (without catalysts) with moderate and high calorific values irrespective of their effect on the energy and combustion characteristic of the propellants. It is shown that if the burning rate of a propellant is affected by catalysts, the addition of RDX or HMX to this propellant (in excess of 100%) does not decrease the relative efficiency of catalysis but even increases it somewhat.     

Applying modified hyperbranched polyester in hydroxyl‐terminated polyether/ammonium perchlorate/aluminium/cyclotrimethylenetrinitramine (HTPE/AP/Al/RDX) composite solid propellant

Composite solid propellants demand fine and stable mechanical properties, creep resistance and stress relaxation performance during their long storage and usage time. In this study, modified hyperbranched polyester (MHBPE) was prepared and introduced into HTPE/AP/Al/RDX (HTPE, hydroxyl‐terminated polyether; AP, ammonium perchlorate; RDX, cyclotrimethylenetrinitramine) solid propellant as an effective additive. The static tensile and dynamic mechanical properties of this propellant before and after the introduction of MHBPE were evaluated. The elevated interfacial interaction by using MHBPE between the binder and RDX fillers improved the toughness and elasticity of the propellant. The enhancement mechanisms were also confirmed by the influence on the fracture surface morphology of the binder which was investigated by SEM. In addition, some influence on the dynamic mechanical properties of HTPE/AP/Al/RDX propellant caused by MHBPE was investigated by dynamic mechanical analysis. The creep behaviors of the HTPE/AP/Al/RDX propellants with and without MHBPE were also investigated at different stresses and temperatures. Reduced creep strain rate and strain were obtained for the modified propellant, implying enhanced creep resistance performance. The creep properties were quantitatively evaluated using a six‐element model and the long‐term creep performance of the propellant was predicted using the time–temperature superposition principle. A creep behavior of nearly 10⁶ s at 30 °C could be acquired in a short‐term experiment (800 s) at 30–70 °C. Moreover, the stress relaxation investigation of the propellants with and without MHBPE at ?40 °C, 20 °C and 70 °C suggested that MHBPE/HTPE/AP/Al/RDX propellant possessed better response ability to deformation. Thus, the application of MHBPE provides an efficient route of reinforcement to enhance the creep resistance and stress relaxation properties. © 2020 Society of Chemical Industry     

提高螺压高能改性双基推进剂性能的研究

研究了Ａｌ粉、ＲＤＸ及高氮量硝棉对螺压高能改性双基推进能量的贡献，配方选择了比较合适的Ａｌ粉、ＲＤＸ含量，解决了采用高氮量硝棉的推进剂的力学性能问题。另外对含能催化剂进行了开发研究，并成功地用在火药中，使得螺压高能改性双基推进剂的性能有了大幅度的提高。     

Influence of Particle Size on the Combustion of CL‐20/HTPB Propellants

The effect of nitramine particle size on the combustion behavior of inert binder based propellants has been extensively studied for RDX and HMX, but not CL‐20. Although materials such as RDX and HMX are useful for particular combustion applications, CL‐20 has a greater potential to improve the oxygen balance and energy density of a propellant. The current work investigates the effect of CL‐20 particle size on the combustion of CL‐20/HTPB propellants down to submicrometer sizes. An influence of particle size on the burning rate and combustion mechanism is reported. The 30 micrometer formulation burning rate data showed evidence of convective burning specifically at higher pressures, but the pressure dependence was comparable to neat CL‐20 at pressures below 8 MPa. A change in the combustion mechanism of the submicrometer formulation as a function of pressure was determined to be a result of the interaction of the propellant flame and the combustion residue. Data suggested that at low pressures diffusion in terms of active cooling was dominant for the submicrometer formulation. Higher pressure data for both the submicrometer and 3 micrometer formulations suggest the degree of active cooling is decreased as the burning rate pressure exponent is near 0.5 for both propellants. The indirect evidence for the presence of a melt layer for CL‐20 propellants is discussed.     

高固含量推进剂模压工艺

探索了一条高固含量推进剂较安全的成型工艺路线,重点介绍了一种高固含量球形药工艺.采用内溶法制得纯硝化棉黏合剂体系及硝化棉与ETPE(含能热塑性弹性体)混合黏合剂体系的高固含量(RDX(黑索今)质量分数为55％～60％)球形药,其球形药密度接近理论计算值,颗粒饱满,粒度均匀致密.采用模压成型工艺将其压制成推进剂药柱,药柱经无损检测,均匀致密,内部无气孔.同时药柱进行了各项性能实验.研究结果表明:该工艺方法简单可行,安全可靠.