水基浆料涂覆结合原位反应制备Cf/SiC复合材料表面光学涂层

摘要

A novel surface modification method for Cf/SiC composites is proposed with aqueous slurry painting together with reaction bonding.Stable slurries were obtained by dispersing SiC to carbon black in aqueous solution,under centain binder content and solid loading conditions.The results show that porous carbonaceous C/SiC tape with porosity of 49％ could be obtained by aqueous slurry painting.Si/SiC coating with high density and strong bonding onto the substrate is realized by infiltrating liquid silicon into the as-prepared tape.A reaction layer of ～15μm in thickness is formed between the coating and the substrate.This Si/SiC coating exhibits excellent mechanical properties,with HV hardness of (14.19 ± 0.46) GPa and fracture toughness of (3.02 ± 0.30) MPa·m1/2.The coating is achieved fine surface of 2.97 nm RMS in roughness after precision grinding and polishing.%本研究提出一种C?SiC复合材料表面改性新方法为水基浆料涂覆结合原位反应烧结工艺.系统研究了SiC和炭黑在水基浆料中的共分散、粘结剂的量和浆料固含量对浆料流变性能的影响、涂层的微观结构和性能等.研究结果表明:采用水基浆料涂覆工艺可在基材表面制备一层气孔率达49％的多孔C/SiC预涂层;通过液相渗硅原位反应工艺,多孔预涂层转变为高致密、与基材强结合的光学涂层,并且在涂层与基材间形成了～15μm的化学反应过渡层;Si/SiC涂层的维氏硬度为(14.19±0.46) GPa,断裂韧性为(3.02±0.30) MPa·m1/2;经过精细研磨抛光,涂层的表面粗糙度可达2.97 nm RMS.