Study On High Radiation Infrared Absorbing Coating Of Cold Detector For Infrared Detector

IR absorption materials as the good performance of infrared radiation are widely used in various industries. Currently, compared with foreign country the research and developing about the cold-shield material which is used in the second generation of infrared detector dewar is more less. Especially for the infrared coating inside to absorb stray was much rarer. Therefore, the research and developing of infrared radiation coating which is used to absorb the stray light has broad application prospects.The development and application status of infrared high radiation absorption coatings have been described, and the material resources, instrument, preparation technology and detection means needed to this experiment have been introduced. Through a large number of experiments, the property influences of coatings were determined. Infrared radiant base materials were from the mixture of SiC, Fe3O4, C and a small quantity of ball milling dispersant. According to TG-DSC test results, the base material sintering process was determined:for slow heating to a high sintering temperature at1400℃with N2atmosphere protection, and then furnace cooling.At last, a certain amount of binder material was added, and a good thermal shock resistance of the infrared radiation paint were prepared.In the design of experimental program, full wavelength infrared radiation rate, the coating thermal stability and thermal shock resistance were the main factors to determine the coating formulation and processing parameter. The great influence factors of emissivity of coating included material structures, the sintering process, and coating preparation process. Through a lot of experiments to explore and compare,it is selected that the best grinding amount of dispersant, carrier binder proportions and the best ingredients ratio. At the same time, the preparation and various process of coating were studied and identified. The research showed that the greatest impacts of the coating process contained two sides:base materials’ sintering process and the coating’s drying temperature. Base materials’sintering process was determined by experimental study, it is heated to800℃(holding1h),then1250℃(holding1h) and reached at1400℉(holding2h). The modern analytical detection methods such as XRD, SEM, XPS, etc were used to detected Infrared radiation paint and coating phase, chemical valence, microstructure and radiation performance. After testing, it was found that there was a certain crystal transition, which provides the basis for ensuring high infrared radiation and thermal stability and good thermal shock resistance.The high radiation infrared absorption coating of infrared detector cold shield was successful prepared. These technologies improved coating’s infrared emissivity, improved the ability to absorb stray light, enriched researches on such coating, fill the domestic blank on the research of this kind of coating. And it has a certain reference role on the future independent research and development about this kind of product.