Co-W-WC配比对传感器用HVOF制备SiO2膜组织及光学性能的影响

Effect of Co-W-WC Proportion on the Microstructure and Optical Properties of SiO Film Prepared by HVOF for Sensor

采用超音速火焰喷涂工艺(HVOF)制得不同配比的Co-W-WC吸收层,之后在上述吸收层表面继续通过Sol-Gel方法制得SiO_(2)复合膜,测试了其微观组织及光学性能。研究结果表明:复合膜中形成了Co、W与WC特征峰,有些Hcp-Co颗粒在喷涂阶段转变成Fcc-Co结构。逐渐提高WC的加入量后,复合膜表面形成了更少的弥散态未熔颗粒,获得了光滑致密组织。W:WC达到1:1时,有助于降低表面粗糙度,使吸收层获得更低发射率。逐渐减小W/WC比值后,反射率发生增大,吸收率下降,表明W具备比WC更强的光谱吸收能力。SiO_(2)薄膜因具备较小的折射率,有助于短波光线透过,因此吸收层可以获得更多入射光。经过100 h热处理后,吸收率增大至0.915,发射率达到0.2516,并未观察到复合膜脱落的情况,表明SiO_(2)复合膜具有稳定的光学性能稳定。

The absorption layers of CO-W-WC with different ratios were prepared by supersonic flame spraying(HVOF).Then the SiO_(2) composite film was prepared on the surface of the absorption layer by the sol-gel method,and its microstructure and optical properties were tested.The results show that characteristic peaks of Co,W,and WC are formed in the composite film,and some Hcp-Co particles transform into Fcc-Co structure in the spraying stage.After gradually increasing the amount of WC,fewer dispersive unmelted particles were formed on the surface of the composite film,and a smooth and dense structure was obtained.When W:WC reaches 1:1,it helps to reduce the surface roughness and make the absorption layer obtain lower emissivity.After gradually reducing the ratio of W/WC,the reflectivity increases and the absorption decreases,indicating that W has a stronger spectral absorption capacity than WC.SiO_(2) thin films have a low refractive index,which facilitates the transmission of shortwave light so that the absorption layer can obtain more incident light.After 100 h heat treatment,the absorptivity increased to 0.915 and the emissivity reached 0.2516.No composite film shedding was observed,indicating that the SiO_(2) composite film has stable optical properties.