Preparation Of SiBN Fibers Sizing Agent And Modification Of Fibers Surface Treatment

SiBN fibers are lightweight,high temperature resistant and irradiation resistant and have great potential for use in aerospace applications.However,SiBN fibers are brittle materials and are prone to brittle breakage during the weaving process,with insufficient strength and toughness.This is why it is so important to modify the surface of SiBN fibers.In this paper,SiBN fibers are modified by sizing to improve the agglomeration of SiBN fibers,reduce the amount of hairy filaments,enhance the surface and mechanical properties of SiBN fibers and improve their weaving performance.The surface treated SiBN fibers were then treated with a sizing agent and subjected to comprehensive performance tests for sizing rate,high temperature treatment residual rate,hardness,tensile strength and friction resistance,and characterised by scanning electron microscopy for changes in fibers properties before and after sizing agent treatment.The performance of the SiBN fibers sizing agent is evaluated according to the changes in SiBN fibers properties.The subject is divided into three main parts,which are studied as follows.Firstly,a stable and homogeneous sizing agent emulsion was prepared using diethylene glycol ether as the organic solvent.The surface desizing conditions of SiBN fibers were explored,and the high-temperature calcination method at 500 degrees Celsius for 2 minutes was determined to improve the interfacial bonding strength of SiBN fibers.Subsequently,the desized SiBN fibers were subjected to impregnationbased sizing treatment,followed by solvent evaporation using a heat drying method.A comparative study was conducted to analyze the performance changes of SiBN fibers before and after sizing treatment.The results demonstrated a significant improvement in the tensile mechanical strength of the fibers after sizing treatment,along with a reduction in fuzz generation,and enhanced flexibility and abrasion resistance.Furthermore,eco-friendly water was employed as a solvent to prepare the sizing agent.The formulation was optimized using orthogonal experimental design,resulting in a stable emulsion-type sizing agent that exhibited long-term storage stability without flocculation,precipitation,or layering.The sizing treatment using this agent led to an increase in the tensile strength of SiBN fibers,a reduction in fuzz generation,a decrease in stiffness,and an increase in abrasion resistance.Lastly,a UV-curable sizing agent was prepared by incorporating oligomers,monomers,photoinitiators,and additives into the sizing agent.The UV-curable sizing agent exhibited excellent clarity,stability,and was applied to SiBN fibers using a spray coating method,followed by UV irradiation to remove residual solvents from the fiber sizing.The film-forming properties of the UV-curable sizing agent and the performance changes of the fibers before and after sizing were studied.Surface morphology and mechanical properties of the fibers were evaluated using SEM and tensile tests,which demonstrated that the developed sizing agent and surface treatment method significantly improved the interfacial performance of SiBN fibers.After sizing treatment,the fibers exhibited noticeable enhancements in surface properties and mechanical strength.