陶瓷纤维织物表面TaSi_(2)-SiC高发射率涂层的制备及性能研究

Preparation and Properties of TaSi_(2)-Sic High Emissivity Coating on Ceramic Fiber Fabric

陶瓷纤维柔性隔热毡表面红外辐射能力较弱并且长时间在高温环境下服役纤维易发生析晶失效。针对上述问题,本文在柔性隔热毡表面制备了双组分TaSi_(2)-SiC高发射率涂层,以提高隔热毡的耐温性能。相较于单组分的SiC涂层而言,室温下的双组分TaSi_(2)-SiC涂层表面结构连续且均匀,并且TaSi_(2)的引入有利于促进涂层高温烧结,提高涂层表面的致密性,阻挡外界热量进入纤维基体内部。双组分T3S1(发射剂TaSi_(2):SiC质量比为3:1)涂层纤维织物经1100℃热处理后仍有较高的拉伸强度约为85MPa,相较于同等条件下的纤维裸布高出19%。此外,涂层中TaSi_(2)与SiC形成协同机制,促进了短波段的红外吸收,明显提高了纤维织物在2~6μm短波段的发射率,T3S1双组分涂层纤维织物在此波长范围内的发射率高达0.955。

The infrared radiation ability of ceramic fiber flexible insulated mat was weak and the fibers was prone to crystallization failure when it was served at high temperature for a long time.To solve the above problems,a double-component TaSi_(2)-SiC high emissivity coating was prepared on the surface of the flexible thermal insulation felt in order to improve its temperature resistance.Compared with the single-component SiC coating,the surface structure of double-component TaSi_(2)-SiC coating at room temperature was continuous and uniform,and the introduction of TaSi_(2)was beneficial to promote the sintering of the coating at high temperature,improve the density of the coating surface,and prevent the heat from entering the fiber matrix.When the mass ratio of the emittance was TaSi_(2):SiC-3:1,the tensile strength of the T3S1-coated fiber fabric after heat treatment at 1100°C was about 85 MPa,19%higher than that of the fiber bare fabric under the same condition.In addition,a synergistic mechanism between TaSi_(2)and SiC was formed in the coating,which promoted the infrared absorption of the short-wave band,and significantly improved the emissivity of the fiber fabric at 2~6μm short wavelength range.The emissivity of the fiber fabric with T3S1 double-component coating was up to 0.955 in this wavelength range.