【作者】 李煜；

【导师】 徐复铭； 周伟良；

【作者基本信息】 南京理工大学 ， 材料科学与工程， 2010， 博士

【摘要】 可燃药筒是一种多孔结构的非均质复合材料,具有容器和提供装药能量的双重作用。可燃药筒可减轻弹药重量,增加随行载弹量；燃烧后自行消失,没有退壳和废壳堆积问题；药筒能量可起到部分发射药作用,提高弹丸初速；其制造工艺简单,成本低廉,便于战时大量、快速生产。可燃药筒的出现促进了火炮结构和装药结构的改进,并使模块化装药得以实现。然而可燃药筒的力学性能与燃烧性能是一对矛盾体,药筒结构的疏松多孔有助于燃烧,但却使得力学性能降低,结构致密时则相反,如何同时提高力学性能和燃烧性能是可燃药筒研究的一大难题。而随着现代的高膛压、高初速武器以及模块化装药技术的发展,对可燃药筒的燃烧性能和力学性能都有了更高的要求。本课题从提高可燃药筒能量角度入手,以提高体系中能量组分的含量来改善可燃药筒的燃烧性能。设计制造了一种含能纤维材料,用以提高模压可燃药筒的能量,改善药筒强度。以含能纤维部分替代硫酸盐木浆纸组分设计了一组可燃药筒配方。通过对配方的氧平衡与热力学参数计算,分析了纤维改性可燃药筒的燃烧性能,并与聚丙烯腈纤维增强的配方进行对比,以现行抽滤模压工艺制备了纤维改性可燃药筒。以氮气吸附孔径分布测试仪、压汞仪和电子显微镜等手段对所制纤维改性可燃药筒进行了微观结构分析。可燃药筒孔隙主要为长条状的狭缝形和楔形孔。通过压汞试验结合Menger海绵体构建了可燃药筒体积分维模型。以基体分维DH和孔隙分维Dv来表征可燃药筒中组分间的孔隙分布和组分的孔隙分布。以材料力学试验机、热分析仪、密闭爆发器试验和高低温交变湿热试验对纤维改性可燃药筒的力学性能、热分解特性、燃烧性能及吸湿性能进行测试分析。相比基础配方B可燃药筒,加入9%含能纤维的可燃药筒的压缩力与抗拉强度分别提高6.8%和17.2%。但随含能纤维替换量增大,可燃药筒的力学性能下降。加入9%含能纤维的可燃药筒定容燃烧结束时间为5.45ms,火药力为590.8 J·g-1;当含能纤维加入量达到16.5%时,可燃药筒燃烧结束时间缩短至1.64ms,火药力增加到664.6 J·g-1;而基础配方B可燃药筒的定容燃烧结束时间为7.63ms,火药力为536.9 J·g-1。结果表明,加入含能纤维有利于缩短可燃药筒燃烧时间,增加火药力,改善其燃烧性能。模拟装药射击试验表明,加入含能纤维后的可燃药筒有利于降低装药的发射烟、焰。定容燃烧试验中,随可燃药筒装填密度的提高,可燃药筒燃烧速度加快,燃烧更为充分,由0.12和0.16 g·cm-3装填密度下测得火药力为583.9 J·g-1,而0.16和0.20g·cm-3装填密度下测得火药力为602.8 J·g-1。随点火强度提高,可燃药筒燃烧速度加快,能量释放更完全,0.12和0.20 g·cm-3装填密度下,弱点火和强点火时测得火药力分别为590.8J.g^-1和672.5 J·g^-1可燃药筒的多孔结构是影响其吸湿速率的关键因素,材质对吸湿量影响较大。药筒吸湿性较强,吸湿速率快。在20℃RH80%条件下,基础配方B可燃药筒吸湿率达到3.91%。含16.5%的含能纤维的可燃药筒在20℃RH80%条件下,吸湿率为3.43%。吸湿后药筒燃烧速度明显下降,0.20g.cm^-3装填密度下,吸湿量为1.6%可燃药筒的燃烧结束时间由干燥样品的6.64ms大幅延长至12.02ms,并且低装填密度下的燃气生成速率波动明显。更多还原

【Abstract】 Combustible cartridge case was a kind of porous composite energetic materials, with dual roles of the container and the energy component. There were no back shells and salvage-shells problems with combustible cartridge case. Using combustible cartridge could reduce the weight of ammunition to increase the bombs loading weight, improve artillery operating conditions and shooting speed, and reduce the arduous task of recovery and transportation. The manufacturing process of combustible cartridge case was simple and low cost, and easy for fast and stack production in wartime. It also saved lots of precious metal materials. The combustible cartridge had resulted in the improvement of artillery and the modular charge system. But the porous structure also led to a contradictionary problem between mechanical properties and combustion properties. Accompanying with the modern high-velocity weapons and modular charge technology improvement, higher standards of combustion performance and mechanical properties of the combustible cartridge were required.This thesis studied the way of improving the combustion performance of combustible cartridge by increasing the content of energetic components. A novel energetic fiber have been designed and manufactured in this thesis. This novel energetic fiber could improve the combustion performance of combustible cartridge and it also had strengthing effect,. Series of modified combustible cartridge had been designed and manufactured by using this novel energetic fiber as strengthing components. As the adding amount of energetic fiber increased, cartridges oxygen balance greatly improved, and enthalpy of formation of combustible cartridge increased. The improvement of energy levels was theoretically beneficial to the improvement of combustion performance.The microstructures of modified combustible cartridge cases were investigated by gas adsorption and desorption analyzer, mercury instrusion porosimeters (MIP) and electron microscopy. Pores of cartridge case were mainly slit-shaped and wedge-shaped. The fractal model of pore structure of combustible cartridge cases was established by virtue of the fractal geometry, through combining Menger sponge with MIP test. The backbone fractal dimension (DH) was formed by the component’s space and influenced by the amount and size of components; percolation fractal dimension (Dv) represented the pore structure of components themselves.Mechanical properties, combustion performance and moisture adsorption of modified combustible cartridge cases have been studied through materials mechanics testing machines, closed-bomb tests and temperature-humid alternating tests, respectively. The influences of different component content, test conditions and other factors on combustion properties of the combustible cartridge have been deeply studied. Compared with basic formula B combustible cartridge, the compression strength and tensile strength of formula PNF9 which added 9% energetic fiber increased 6.8% and 17.2%, respectively. As the energetic fibers adding amount increased, combustible cartridge mechanical performance declined.In constant-volume combustion, the burning-off time and impetus of formula PNF9 which added 9% energetic fibers were 5.45ms and 590.8J/g, respectively. While, the burning-off time and impetus of basic formula B were 7.63ms and 536.9 J/g. As the energetic fiber content increased, gas generation rate boosted and burning-off time shortened, combustion performance improved. The charge simulation test revealed that adding energetic fibers could also reduce the solid residues and combustible gases.In constant-volume combustion experiments, as loading density increased, the gas generation rate of combustible cartridge became faster, the combustion became more effective, cartridges energy released more complete. The impetus tested under 0.12 and 0.16 g/cm3 loading densities was 583.9 J/g, while it was 602.8 J/g under 0.16 and 0.20 g/cm3 loading densities. With the ignition power increased, the burning rates were accelerated, cartridges energy release were more complete. Under 0.12 and 0.20 g/cm3 loading density, impetus improved form 590.8 J/g of weak-ignition to 672.5 J/g of strong-ignition.The porous structure and component materials strongly affected the moisture adsorption of combustible cartridge. Moisture adsorption rate of formula B cartridge reached 3.91% under 20℃and RH80%. After adding 16.5% energetic fiber, moisture adsorption rate dropped to 3.43%. The gas generation rate decreased significantly after adsorpted moisture, and became more volatile in lower loading density. Under 0.20g/cm3 loading density, the burning-off time of combustible cartridge with 1.6% moisture extended from 6.64 ms of dry sample to 12.02 ms.更多还原