镀镍碳化硅纤维红外消光率研究

Infrared Extinction of Super-fine Ceramic Fiber Coated Nickel

以表面镀覆金属的超细陶瓷纤维为研究对象，从介质与入射电磁波相互作用的角度出发，应用电磁场数值模拟技术预估陶瓷纤维材料在军用红外波段消光率随材料本征属性变化的规律，着重研究消光率发生突变时上述参量对应的值域区间。研究发现：纤维的长径比对消光截面影响很明显，尤其是在中远红外波段，当长径比在20～200之间变化时，消光截面增加很快；当纤维长径比取值在50—200范围时，对应的折射率虚部小于20可获得理想的消光率；复电导率实部在10^6～10^8 s／m范围内时，纤维的消光截面较大。依据计算结果，通过控制化学镀工艺条件制备出满足要求的功能材料，并利用溴化钾压片法和小型烟箱实验对镀覆前后陶瓷纤维的质量消光系数进行对比，实验数据证实镀镍碳化硅的红外消光性能显著提高。

From the viewpoint of interaction between medium and incidence electromagnetic wave, the extinction section of fiber coated nickel was estimated by method of electromagnetic field numerical simulation. It was researched that extinction changed with material properties, including aspect ratio of fiber, conductivity, refractive index, and dielectric constant. The results showed parameter regions corresponded to mutation of extinction section. Aspect ratio of fiber influenced the extinction section, especially at middle-near infrared frequency. While aspect ratio was 20 - 200, image of refractive index was smaller than 20 and real of conductivity of ceramic fiber was 10^6 - 10^8 s · m ^-1, extinction section would be increased rapidly. According to calculated results, nickel coated ceramic fiber was prepared with method of chemistry plating. The extinction coefficients were contrasted between metal coated fibers and uncoated fiber measured by potassium bromide press and smoke box. The data showed that mass extinction coefficient of nickel coated carborundum was enhanced obviously, in far infrared range.