Research On Preparation And IR/MMW Characteristics Of Combustible Foil

The infrared pyrotechnicscomposed of Mg/PTFE/Viton(MTV)can generate intense infrared radiation by burningwhichcan simulate the radiation characteristics of the target to countermine the infrared guidance weapons.But with the emergence of infrared-MMW compound guidance weapons,the MTV pyrotechnics can not countermine the new guidance weapons effectively because of the high burning temperature of MTV and the radiation spectrum differences between the MTV decoys and real targets.According to the interrelated theory of pyrotechnic radiation and millimeter wave scattering,this study coats the pyrotechnic on one side of the foil substrate to prepare the combustible foil,we reduce the radiation energy and improve the spectrum distribution by design the pyrotechnic compositions and the foils.The infrared radiation and MMW characteristics and the application of the combustible foils are studied.Based on the infrared radiation characteristics of the pyrotechnics and the MMW characteristics of the foils,the technics of preparation the combustible foil are studied.The combustible foils are prepared by different methods,includes vertical injection method,viscosity adherent method,external diffusion method and gravity deposition method.The results show that the combustible foil prepared by gravity deposition method is stronger,the pyrotechnics distribution is uniform,the thickness is controllable.On this basis,the influence ot the preparation parameters,such as mass of pyrotechnics and the size of the combustible foil,on the molding,burning and radiation characteristics are studied.The results show that coating 10g pyrotechnics on the 10cm×10cm foil substrate is better.On account of the intense infrared radiation of MTV,the influence of the change of the pyrotechnic composition on the preparation,burning and radiation characteristics on combustible foil are studied by adjusting the variety,size and proportion of the components.Using the SC7000 far-infrared thermal imager measure the burning temperature,radiance,radiation area and so on,using OPAG33 FTIR remote-sensing spectrometer measure the infrared spectrum distribution of the combustible foil,the pyrotechnic consists of the 48%RF-PTFE,52%P-Mg with the size of 150-200 mesh and 10%Viton is chosen as the basic formula.According the study and analyze of the theory of pyrotechnic radiation,the way of adding EG,thermites and LH into the basic formula to reduce the burning temperature and add radiation burning productions which have intense radiation in middle and far infrared bands are proposed.The infrared radiation characteristics are tested by the SC7000 and OPAG33,and the results show that the EG which can physical expansion to impede burning reduces the burning temperature of the combustible foil by 20-29%,the radiation shifts to the 3-5 μm bands.The infrared radiation of the burning products are tested by the Fourier Infrared Spectrometer,and the results show that the thermites and LH can generate gas and solid products which have radiation peaks in middle and far-infrared bands.Thereby they can improve the infrared radiation in middle and far-infrared bands of the combustible foils.On the basis of the millimeter wave scattering theory,the MMW scattering characteristics of combustible foil are studied by the 3 MMW radar scattering cross-section measurement radar,in order to achieve the combustible foil material which has the suitable MMW scattering characteristics.The results show that,the RCS increases with the increase of the metal substrates’ conductivity.The RCS first increases quickly then tend to stable with the increase of the area of the substrates.Comparing the RCS of different shape substrates,including round,square,rhombus and the tall fin type,the results show that the RCS of the tall fin type is biggest,which is 1.208m2.The pyrotechnics reduce the MMW scattering characteristics sharply(reduced by 80%).The CF which can resistant to high temperature can observably increase the MMW scattering characteristics of the pyrotechnic side of the combustible foil,and the RCS increases linearly with the increase of CF.Experimenting the ignition,dispersion,burning and radiation characteristics of combustible foils by explosion dispersion and dispersion,the results show that the radiating area increases to the maximum 10.95m2 at 1.88s,and the radiating temperature reaches the maximum 732.30℃ at 0.88s.Comparing the different quantity,shape of the combustible foils,the relationship between the single combustible foil and the radiation cloud,we find that the main factors influencing the burning and radiation characteristics of radiation cloud are the mass of the pyrotechnics,quantity of the combustible foils and the burning and radiation characteristics of the single combustible foil.