Design And Performance Study Of Low Burning Temperature Infrared Decoy Compositions

With the continuous progress of infrared guidance technology,the target recognition ability of guided weapons is getting stronger and stronger,and the survival of military targets in the battlefield is facing great threats and challenges.The traditional MTV infrared compositions is not suitable for the interference of infrared guided weapons because its great burning temperature（2000-2500K）making its radiation band concentrated in the short wave band.Therefore,it’s of great significance to study infrared decoy with low combustion temperature for the survival of battlefield targets.Aiming at the problem that the narrow measuring range of the temperature measuring system cannot meet the measurement of the combustion temperature of the compositions,the temperature measuring range of the system is widened by preposing neutral density attenuators with different transmit tance.Then,aiming at the frequent calibration caused by the adjustment of attenuator and integration time when measuring radiation sources in different temperature ranges,a wide dynamic range radiation calibration model considering both integration time and transmittance of attenuator is established by analyzing the calibration theory,and a simplified calibration method is proposed.Experiment results showed that the method has higher temperature measurement accuracy while improving calibration efficiency within a certain tolerance range.According to the infrared decoy suitable for the protection of relatively low temperature targets,Al and Ti are selected as combustible agents and Ba（NO ₃）₂、Fe₃O₄、Pb₃O₄、Cr₂O₃ are selected as oxidizing agents through the analysis of the phys ical and chemical properties of the materials.Eight groups of flameless infrared decoy formulations with low combustion temperature were designed according to the oxygen balance theory.The combustion equilibrium products and energy characteristic parameters were calculated by NASA-CEA software,and the combustion products and combustion temperatures of the formulations were predicted.After that,the thermal decomposition performance,combustion performance and radiation performance of the samples were studied through thermal synchronization analysis and combustion radiation test experiments.Finally,the phase analysis of the combustion products of the samples was carried out by the XRD experiments.The results showed that the mass burning rate of samples containing titanium is higher under the same oxygen balance;When selecting Ba（NO₃）₂ as the oxidant,the scalding products with slow radiation attenuation were formed by the compositions when the oxygen balance is high enough.When Fe₃O₄ and Cr₂O₃ are selected as oxidants,samples containing Al can form more products and the attenuation rate of radiation intensity slows down with the increase of absolute value of oxygen balance at both middle and far wave bands,while samples containing Ti can form scorching products with slow attenuation rate of infrared radiation intensity at both middle and far wave bands only after|OB|≥0.60 and|OB|≥0.45 respectively.Both Al-containing and Ti-containing samples can form more scalding products with slow attenuation rate of infrared radiation intensity at both middle and far wave bands when Pb₃O₄ is selected as oxidant.According to the infrared compositions suitable for the protection of relatively high temperature targets,two groups of flamed low-temperature infrared decoy formulations were designed based on Mg/PTFE（1/1）and Mg/Pb₃O₄/PTFE（10/7/3）by adding different proportions of Zn/Pb₃O₄ and P/C₁₀H₈ components,respectively.And the combustion equilibrium products and energy characteristic parameters were calculated.After that,thermal decomposition performance,combustion performance and radiation performance were studied respectively through thermal synchronization analysis and combustion radiation test experiments.The results showed that the addition of P/C ₁₀H₈component and Zn/Pb₃O₄ component can reduce the temperature and enthalpy of the main reaction peak.And the combustion temperature of the samples can indeed decrease with the addition of Zn/Pb₃O₄ ratio,but the mass burning rate,radiance,radiation area and radiation intensity also decrease as well.The mass burning rate of the samples gradually decreases and the burning temperature increases first and then decreases with the addition of P/C₁₀H₈ components.The radiation area and radiation intensity of the samples increased by 2%～24.71%and 5.05%～32.03%respectively compared with the basic formula as the addition ratio of P/C₁₀H₈ ranging from 3% to 12%.