Phase-Changed Thermal Infrared Stealthy And Composite Tempereture-Control Coatings

Thermal Infrared Stealth is a hot topic in recent years in the military field and domestic scientific research units have a lot of input. In the whole, the subject remained at a level of low emissivity coating and explore the thermal fusion principle of stealth coatings. The core material of thermal fusion stealth coating is phase-change materials, and phase change micro-capsules is the most common fact. Research trouble is low latent heat and the phase- change temperature range is relatively narrow of the microcapsule, that is limited temperature-control capacity to reach large latent heat of stealth targets. So, enhance the latent heat and expand the phase transition temperature range is becoming a more meaningful research. This article prepared one kind of phase change materials with high latent heat, wide phase changed temperature range. Based on it, the article developed two kinds of thermal fusion stealth coating, the coating efficiency increase a lot.Use paraffin as phase change materials, low melting point of unsaturated fatty acids for the modified materials, prepare PCM in middle temperature with high latent heat(26J / g), wide phase changed temperature range(20 ~ 50℃) by high efficiency single coagulation method that provides greater latent heat of stealth additives for the phase transition stealth coating(PSC) later.Prepare PSC with PCM as the filler by Use of coatings technology to develop their own micro-capsules for the stealth filler, coating morphology were observed, stealth filler was uniformly distributed , no large reunion, block phenomenon of phase change microcapsules retained uniform temperature-controlling function; Thermal properties of the coatings were studied by differential scanning calorimetry, the latent heat and phase transition temperature range is closed to theoretical values, and further validate that phase-changed stealth coating retains the temperature-controlling capacity of PCM; Applied the PSC to the model stealth tanks, do some test of stealthy of tanks in the high temperature-large temperature difference and low temperature-small temperature difference environment. It reached the conclusion that PSC have a high stealthy efficiency in low temperature-small temperature difference environment but low in high temperature-large temperature difference environment, provided foundation for the decision of composite temperature-controlling stealthy coating(CCSC).In high temperature-large temperature difference environment, prepared paraffin/HDPE composite material with HDPE as the support body, paraffin as the core material. Coating morphology appeared that wax particles was uniformly distributed in the net of HDPE, it was the"micro-thermal storage room"which is equivalent to the cell structure of PCM. The result of thermal analysis is that latent heat is 89J/g, it provided a kind of thermal fusion stealthy materials. Developed CCSC, combining this coating with deformation camouflage, enhanced the capacity of thermal fusion stealthy.Test the stealthy efficiency of PSC and CCSC by thermal imager Fluke-ti10 in the standard environment. Conclusion is that PSC is more suitable for low temperature target and CCSC is more suitable for high temperature target. Meanwhile, the quantitative calculation of the stealth efficiency of the composite have done, the efficiency was as high as 57% or more.