| With the rapid development of military electro-optical technology, the military objects in the sky have been threatening more and more seriously by optoelectronic and infrared (IR) detectors. Advanced photoelectric reconnaissance devices, high precision electro-optical guided surface-to-air missile and air-to-air missile together makes modernized aircrafts difficult to escape from being discovered. And modern military technology has been achieved to the level of"Object can be destroyed when it was discovered". Therefore, to enhance survivability of military targets, we must find the ways which can decrease targets' detection probability, here, IR stealthy materials would be a wise choice.In allusion to the status of study on IR stealthy materials at home and abroad, the existing IR stealthy materials are summarized in this paper. Based on mechanism of IR camouflage, the technology of chemical plating and technology of material surface coating were adopted to prepare two type low emissivity IR stealthy materials——materials of surface modified barium ferrites by chemical plating and composite materials of Al-powder coated with IR transparent metal oxides. Then the manufacture process of products was optimized and effect of technology parameters on samples'IR emssimivity was studied, respectively.In optimizing process parameters of chemical plating on barium ferrites, influence of main salt dosage, reducing agent dosage, complexing agent dosage, pH value, reaction temperature and etc. on samples' IR emissivity has been investigated. Results showed that: The best technological conditions of electroless Ni-P and Ni-Co-P plating on barium ferrites is that loadage is 4g/L, nickel sulphate is 30g/L, sodium hypophosphite is 20g/L, sodium citrate is 70g/L, ammonium sulfate is 50g/L, reaction temperature is 85℃, pH value is 10.0 and loadage is 4g/L, nickel-cobalt sulphate is 30g/L, the optimal ratio of nickel sulphate to cobalt sulphate is 1:1(mass ratio), sodium hypophosphite is 20g/L, sodium citrate is 70g/L, ammonium sulfate is 50g/L, reaction temperature is 85℃, pH value is 10.0, respectively. SEM, XRD, and other modernized analytical methods were used to characterize the sample's surface topography and phase structure. Diffuse reflection system of FTIR was utilized to test IR emissivity of the samples. The results of FTIR test indicated that after nickel plating the IR emissivity (8~14μm) decreased from 0.8915 to 0.5910, and Ni-Co-P plating not only made the IR emissivity low to 0.5854, but also improved magnetic properties of electroplated coating and enhanced Radar absorbing ability of the materials because of Co ion input.In this paper, the NiO/Al composite particle was prepared by the method of homogeneous precipitation, and urea was used as precipitant agent. First, a coat of Ni2CO3(OH)2 precursors is present on Aluminum-powder surface, then Ni2CO3(OH)2/Al was calcined 1.0h at temperature of 450℃, and the NiO/Al composite particle was produced. Using thioacetamide as precipitator, the ZnS/Al composite particle was prepared. The influence of technical parameter of preparation of NiO/Al and ZnS/Al on materials IR emissivity was studied, separately, and the optimal technology parameters were obtained. The composite particles obtained were characterized by SEM, XRD and other analytical methods. The testing results indicated that the composite particles were coated completely, uniformly and densely, besides metallic luster of Al-powder can be completely covered.
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