摘要
使用模压烧结法制备不同PTFE体积分数的PTFE/Al/MoO_3复合材料,借助扫描电子显微镜(SEM)和X射线衍射仪(XRD)对材料进行表征,并研究该复合材料的准静态压缩性能和动态冲击性能。结果表明:PTFE/Al/MoO_3复合材料的强度随着PTFE的增加先增加后降低,当PTFE体积分数为70%时达到最大的80MPa,且该试样能够在准静态压缩条件下发火,发出巨大的爆炸声和明亮的火光,而其他试件在同等条件下未见发火现象。动态冲击条件下,PTFE/Al/MoO_3复合材料均能发生爆炸反应,但随着PTFE的增加,剧烈程度逐渐降低,反应产物为AlF_3,Al_2O_3,Mo,C,表明Al与PTFE和MoO_3都发生了氧化还原反应。在材料强度和组分的双重影响下,PTFE/Al/MoO_3复合材料发火所需能量随着PTFE的增加,呈现先降后升的趋势。
PTFE/Al/MoO_3 composites with different PTFE concentrations were prepared by mold pressing and sintering. The materials were characterized by scanning electron microscopy(SEM) and X-ray diffraction(XRD), in addition, the properties of the composites under quasi-static compression and dynamic impact were also studied. The results indicate that, the strength of PTFE/Al/MoO_3 composites is increased first and then decreased with the increase of PTFE, reaches the maximum of 80 MPa when the volume fraction of PTFE is 70%. Meanwhile, these specimens can ignite under quasi-static compression conditions, with a huge explosion and bright flames, while no ignition phenomenon was observed in the other specimens under the same conditions. Under the dynamic impact conditions, all of the PTFE/Al/MoO_3 composites can ignite, but with the increase of PTFE, the degree of intensity is decreased gradually. The reaction products are AlF_3, Al_2O_3, Mo and C, indicating that the redox reactions of Al and PTFE, Al and MoO_3have both been triggered. Under the dual influence of material strength and composition, the energy required for ignition of PTFE/Al/MoO_3 composites tends to drop first and then increase with the increase of PTFE.
引文
[1] FISCHER S H,GRUBELICH M C.Theoretical energy release of thermites,intermetallics,and combustible metals[C]//24th International Pyrotechnics Seminar.Monterey,CA:IPS Seminar,1998:121-128.
[2] 李向东,钱建平,曹兵,等.弹药概论[M].北京:国防工业出版社,2010:15-16.LI X D,QIAN J P,CAO B,et al.Introduction to ammunition[M].Beijing:National Defense Industry Press,2010:15-16.
[3] SCHOENITZ M,WARD T,DREIZIN E L.Preparation of ener-getic metastable nano-composite materials by arrested reactive milling[J].MRS Proceedings,2003,800:261-266.
[4] UMBRAJKAR S M,SCHOENITZ M,DREIZIN E L.Control of structural refinement and composition in Al-MoO3 nanocomposites prepared by arrested reactive milling[J].Propellants Explosives Pyrotechnics,2010,31(5):382-389.
[5] DUTRO G M,YETTER R A,RISHA G A,et al.The effect of stoichiometry on the combustion behavior of a nanoscale Al/MoO3,thermite[J].Proceedings of the Combustion Institute,2009,32(2):1921-1928.
[6] GLAVIER L,TATON G,DUCéRé J M,et al.Nanoenergetics as pressure generator for nontoxic impact primers:comparison of Al/Bi2O3,Al/CuO,Al/MoO3,nanothermites and Al/PTFE[J].Combustion & Flame,2015,162(5):1813-1820.
[7] KAPPAGANTULA K S,FARLEY C,PANTOYA M L,et al.Tuning energetic material reactivity using surface functionalization of aluminum fuels[J].Journal of Physical Chemistry C,2012,116(46):24469-24475.
[8] SON S F,ASAY B W,FOLEY T J,et al.Combustion of nano-scale Al/MoO3 thermite in microchannels[J].Journal of Propulsion & Power,2007,23(4):715-721.
[9] FERRANTI L,THADHANI N N.Dynamic mechanical behavior characterization of epoxy-cast Al+Fe2O3,thermite mixture composites[J].Metallurgical & Materials Transactions A,2007,38(11):2697-2715.
[10] 钟爱文,姚萍屏,肖叶龙,等.空间摩擦学及其材料的研究进展[J].航空材料学报,2017,37(2):88-99.ZHONG A W,YAO P P,XIAO Y L,et al.Research status and developing trend of space tribology and tribological materials[J].Journal of Aeronautical Materials,2017,37(2):88-99.
[11] 张冬娜,寇开昌,张宇,等.拉伸处理对聚四氟乙烯性能的影响[J].航空材料学报,2013,33(6):57-61.ZHANG D N,KOU K C,ZHANG Y,et al.Effect of stret-ching on properties of polytetrafluoroethylene[J].Journal of Aeronautical Materials.2013,33(6):57-61.
[12] 索进平,肖建中.制备工艺对PTFE复合材料硬度的影响[J].润滑与密封,2005(3):78-80.SUO J P,XIAO J Z.Effect of fabrication process on the hardness of PTFE matrix composites[J].Lubrication Enginee-ring,2005(3):78-80.
[13] 汪萍.聚四氟乙烯的烧结工艺技术[J].工程塑料应用,2001,29(3):19-21.WANG P.PTFE sintering technology[J].Engineering Plastics Application,2001,29(3):19-21.
[14] KOCH E C.Metal-fluorocarbon based energetic materials[M].Weinheim:Wiley-VCH,2012:121-125.
[15] CAI J,WALLEY S M,HUNT R J A,et al.High-strain,high-strain-rate flow and failure in PTFE/Al/W granular composites[J].Materials Science & Engineering:A,2008,472(1/2):308-315.
[16] XU F Y,LIU S B,ZHENG Y F,et al.Quasi-static comp-ression properties and failure of PTFE/Al/W reactive materials[J].Advanced Engineering Materials,2016,19(1):1-7.
[17] FENG B,LI Y C,WU S Z,et al.A crack-induced initiation mechanism of Al-PTFE under quasi-static compression and the investigation of influencing factors[J].Materials & Design,2016,108:411-417.
[18] XU S,YANG S,ZHANG W.The mechanical behaviors of polytetrafluorethylene/Al/W energetic composites.[J].Journal of Physics Condensed Matter,2009,21(28):285401.
[19] 陈志优.金属/聚四氟乙烯反应材料制备和动态力学特性[D].北京:北京理工大学,2016.CHEN Z Y.Preparation process and dynamic mechanical proper-ties of metal/PTFE reactive materials[D].Beijing:Beijing Insti-tute of Technology,2016.
[20] 冯彬,方向,李裕春,等.10-2/s压缩应变率下Al-Teflon的反应现象[J].含能材料,2016,24(6):599-603.FENG B,FANG X,LI Y C,et al.Reaction of Al-Teflon under 10-2/s compression strain rate[J].Chinese Journal of Energetic Materials,2016,24(6):599-603.
[21] FENG B,FANG X,LI Y C,et al.Reactions of Al-PTFE under impact and quasi-static compression[J].Advances in Materials Science & Engineering,2015,2015:1-6.
[22] HUNT E M,MALCOLM S,PANTOYA M L,et al.Impact ignition of nano and micron composite energetic materials[J].International Journal of Impact Engineering,2009,36(6):842-846.