典型气溶胶粉体红外消光性能研究(特约)

Infrared extinction properties of typical aerosol particles(Invited)

气溶胶粉体是烟幕弹药的核心组成部分,其红外消光性能直接决定了烟幕的红外遮蔽效果。选择石墨粉和铝粉两种典型的气溶胶粉体作为研究对象,通过烟箱实验,测量了不同粒径的两种材料的质量消光系数,分析了粉体粒径对气溶胶红外消光性能的影响,探讨了引起两者红外消光性能差异的原因,考察了在烟箱实验中目标温度等因素对测试结果的影响。结果表明:对于所测试的几种样品,在同等条件下,气溶胶粉体粒径越小,其质量消光系数越大,红外消光性能也就越好;铝粉的红外消光性能要好于石墨的,1000目铝粉的中红外(3.7~4.8μm)和远红外(7.5~14μm)质量消光系数为分别为1.78 m^2/g和2.01 m^2/g,显著优于1000目石墨粉体的值(1.02 m^2/g和1.01 m^2/g),石墨与铝粉之间的分散性、径厚比和折射率等特性的差异是导致这一现象的主要原因;烟箱实验中,目标和背景的初始温度对测试结果影响较大,应该对它们进行合理设置,以提高测量的准确性。

Graphite and aluminum powders are typical aerosol particles whose infrared(IR)extinction properties are important to the IR obscuring performances of the smoke ammunitions containing these powders.Mass extinction coefficients(MECs)of the two materials with different sizes are measured in a smoke chamber.The relationship between the powder size and the IR extinction property is analyzed,with the difference between their extinction properties being discussed.Moreover,test accuracy is studied at different temperatures of the target and the background.The results show that the IR extinction property gets better as the size of the graphite powder decreases.Due to its better dispersivity,larger radius-thickness ratio and larger IR refractive index,aluminum powder shows better extinction properties than graphite powder of the same size.The IR MECs of aluminum powder(1000 meshes)are respectively 1.78 m^2/g(3.7-4.8μm)and 2.01 m^2/g(7.5-14μm),with those of graphite powder of the same size being 1.02 m^2/g and 1.01 m^2/g respectively.In addition,test results are found to be closely related to the initial temperatures of the target and the background,showing the necessity of appropriate settings of the temperature.