Study on Preparation and Absorption Properties of Silicon Carbide Composites by Powder Bed Fusion-Reaction Sintering
In this study,the phenolic coating material suitable for powder bed 3D printing was prepared by high-speed stirring.The silicon carbide and carbon fiber green parts were then produced through powder bed fusion.Two types of silicon carbide composite materials containing silicon carbide powder and carbon fiber were obtained through subsequent impregnation and densification or reaction sintering processes.The microstructures,phase characteristics,mechanical properties,and permittivities of the two materials were compared in order to analyze their wave-absorbing properties via calculation.The results indicate that carbon fiber/silicon carbide composite has better mechanical properties and wave-absorbing properties with a bending strength reaching(289±22.4)MPa,bulk density of(2.69±0.05)g/cm3,porosity reaching 0.472%.When the composite thickness is 2.77 mm,the minimum reflection loss(RLmin)of CF-S composite reaches-40.7 dB at 11.14 GHz;when the thickness increased to 6 mm,the RLmin value reaches-35.1 dB at 5.77 GHz.The composite maintains good wave-absorbing performance under high temperature oxidation condition.These research findings provide technology and theory supports for the integrated wave-absorption-structure silicon carbide composites.
Powder bed fusionReaction sinteringSilicon carbide compositeWave absorbingStructure-function integration
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