Ceramic Fiber Surface Coating Preparation And Physical Properties Of The Research

In order to solve the existing problems in the application of fiber materials, the preparation of modified carbon fiber with boron nitride coating and modified glass fiber with metal coating is studied in this article. The addition of boron nitride coating improves the property of high temperature resistance and the insulation performance of carbon fiber, which makes the carbon fiber become a unique high temperature rader absorbing material. By using metal coating, the glass fiber gets better performances in the fields of conduction and antioxidation. These new materials in our research can be used in aerospace field and National Defense.Firstly, after the feasibility analysis based on thermodynamic equation, with boric acid, the BN coating on the carbon fiber surface is perpared by pyrolysis method. By testing means such as XPS、SEM、 XRD、IR, we analysis the BN coating’s composition, structure and morphology. Besides, The tensile strength of a single fiber with BN coating is also tested. These above results show that the continuous and uniform t-BN coating on carbon fiber has been sucessly fabricated. By Adding reducing gas in the nitrogen atmosphere, the heat treatment temperature of boron nitride coating could be reduced to400℃. With analysing and comparing experimental data, the effect degree of different factors on the experiment has been ranked:temperature>time>precursor concentration>gas flow. The opitimality conditions of the experiment have been got:concentration is1.3mol/L, the heat treatment temperature is4hours at400℃, and the insulation hydrogen concentration is80ml/min.Secondly, based on dip coating at different temperature, we use boric acid and urea as the material to preduce boron nitride coating on the carbon fiber. By comparing the experiments with and without urea, the B2O3content in the reaction process slightly increased with the urea. Finally, modified glass fiber with Cu and Zn coating is prepared and tested. Based on the process of electroless copper plating, Cu coating is prepared. The Cu coating is dense and the interface is combined closely. The Zn coating is prepared based on the electroplating process, but it’s rough surface is easily to flake off, Joining brightener material,the coating has improved, the granular crystallization disappeared, appearing part of a cavernous coating.