RDX粒度对硝胺发射药力学性能及燃烧性能的影响

为研究黑索今(RDX)粒度对硝胺发射药力学性能及燃烧性能的影响,设计了RDX质量百分数为25.0%,平均粒径(D50)为30,50,150μm的3种硝胺发射药,采用摆锤式简支梁冲击试验机、落锤试验仪与密闭爆发器分别研究了其抗冲击强度、破碎情况及燃烧性能。结果表明,随着RDX粒度由150μm减小至30μm,发射药的低温(-40℃)抗冲击强度由3.46 J·cm~(-2)提高至8.99 J·cm~(-2),在落锤冲击(锤重5 kg,落高80 cm)作用下破碎度由96%降低到18%。RDX的平均粒径(D50)为30,50μm和150μm时,发射药的燃速压力指数分别为0.985、0.996和1.063。RDX粒径为30μm或50μm时,发射药u-p曲线较光滑,发射药燃烧稳定;RDX粒径为150μm时,在100~150 MPa、150 MPa~p_(dpm)的两个压力段范围内,燃速压力指数由1.125变为0.612,显示燃速压力指数存在突变,发射药燃烧不稳定。

Effect of RDX Particle Size on the Mechanical and Combustion Properties of Nitramine Gun Propellant

To study the effect of RDX particle size on the mechanical property and combustion performance of nitramine gun propellant,three kinds of nitramine gun propellants containing 25.0％ RDX with average particle sizes of 30,50 μm and 150 μm were designed,their impact strength,crushing situation and combustion performance were studied by pendulum charpy impact machine,drop weight test apparatus and closed bomb,respectively.Results show that with the particle size of RDX decreasing from 150 μm to 30 μm,the impact strength of gun propellants at low temperature (-40 C) increases from 3.46 J · cm-2 to 8.99 J · cm-2,and the crushing degree under the action of drop hammer impact (hammer weight 5kg and drop height 80 cm) decreases from 96％ to 18％.When the average particle size of RDX,Ds0,is 30,50 μm and 150 μm,the pressure exponent of burning rate is 0.985,0.996 and 1.063,respectively.When the particle size of RDX is 30 μm or 50 μm,the u-p curve of gun propellant is smooth,its combustion is stable.When the particle size of RDX is 150 μm,in the pressure range of 100 ～150 MPa to 150 MPa ～Pdpm,the pressure exponent of burning rate decreases from 1.125 to 0.612,revealing that there is a mutation in the pressure exponent of burning rate and the propellant combustion is unstable.