Effect Of The ⁶⁰Co-? Ray On Performance Of Low Infrared Emissivity Coating Curved At Room Temperature And Applied At Moderate Temperature

The application of low infrared emissivity coating on aircraft engine hot-section components is one of the effective measures to reduce infrared radiation. The low infrared emissivity coating prepared by our research group, which was cured under 180 degree centigrade for two hours, has good comprehensive performance. That curing conditions the coating needed of large gear device, however, could not be achieved in engineering application, which lead to the poor performance. After the improvement, the coating could be cured under 35 degree centigrade for 48 hours and the performance could be improved to some extent. But, it was also quite worse than previous coating cured under 180 degree centigrade. So, how to make the comprehensive performance of the coatings cured at room temperature further improved without performance degradation of infrared emissivity, has the important practical value.In thesis, the raw materials were irradiated by ⁶⁰Co gamma ray, which were used for preparing the infrared emissivity coating worked at moderate temperature. The irradiation technology parameters obtained by the optimization experiment, which could acquire the higher degree of crosslinking of the coating. Compared with the coating without using irradiation measures, it was proved that the irradiation measures could be effective to solve the problems we met. In this thesis, the obtained research results were as follow:1. Through the theoretical analysis and experiment, it was pointed out that the difference of the degree of link crosslinking could make a large difference in performance between coatings. The mechanism was also analyzed.2. The silicone resins modified by epoxy were irradiated by ⁶⁰Co gamma irradiation and gel fraction of the low infrared coating prepared were tested. The results showed that mechanical property of coatings cured by amines was improved without performance degradation of infrared emissivity between 8¹4?m, since the degree of crosslinking improved.3. On the basis of coatings cured by amines,the irradiation technology parameters were obtained by the optimization experiment according to the gel fraction: The solid contents of the resins was 50%, the Aluminum content added in advance was 40%, filling the nitrogen and the dose was 60 kGy. The gel fraction of the coating prepared by these raw materials was 80.6%.4. The low infrared emissivity coatings prepared according to the results after optimization, which were used at high temperature, were compared to the coatings cured at the same condition without irradiation measures through comprehensive performance. The results showed that the glossiness?60°?, the anti-corrosion resistance and the heat resistance performance was superior by using ⁶⁰Co gamma irradiation without performance degradation of infrared emissivity and the wet-hot aging performance could keep a good, while the anti-ultraviolet ageing performance was as bad as before.