基于直写成型的连续碳纤维增韧碳化硅复合材料制备与性能研究

Research on Preparation and Properties of Direct Ink Writing of Continuous Carbon Fiber Reinforced Silicon Carbide Ceramic Matrix Composites

连续碳纤维增韧碳化硅陶瓷复合材料具有密度低、比强度高、耐高温等优点,在核能、航空航天等高科技领域具有广阔的应用前景。采用直写成型技术,通过同轴喷头同步成形连续碳纤维与碳化硅陶瓷基体,可实现连续纤维增韧陶瓷复合材料的制备及其组织与性能调控。系统研究了碳化硅浆料的固相含量、挤出流量、打印速度与打印层厚度对连续纤维增韧碳化硅直写成型坯体质量的影响,并采用XRD、SEM和力学性能测试手段对其进行了表征。结果表明,在碳化硅浆料中添加短碳纤维,可以进一步提高连续纤维增韧碳化硅复合材料的强韧性;通过先驱体浸渍裂解可减少纤维单丝间隙,使复合材料的弯曲强度达到146MPa,断裂韧性达到3.77MPa·m^(1/2)。研究结果为未来连续碳纤维增韧碳化硅陶瓷复合材料零件的快速制造提供了试验依据。

Continuous carbon fiber reinforced silicon carbide ceramic composites have the advantages of low density,high specific strength,high temperature resistance,etc.,and have broad application prospects in high-tech fields such as nuclear energy and aerospace.Using direct ink writing technology,the continuous carbon fiber and silicon carbide ceramic matrix were simultaneously formed through the coaxial nozzle to realize the preparation of continuous fiber reinforced ceramic composite material and the control of its structure and performance.The effects of slurry solid content,extrusion flow,printing speed and printing layer thickness on the quality of direct ink writing green part were systematically studied,and it was characterized by XRD,SEM and mechanical properties testing methods.The results show that adding short carbon fibers to silicon carbide slurry can further improve the strength and toughness of continuous fiber toughened silicon carbide composites.The polymer infiltration and pyrolysis can reduce the fiber monofilament gap,so that the bending strength of the composite material can reach 146MPa,and the fracture toughness reaches 3.77MPa·m1/2.The research results of this paper provide experimental basis for the rapid manufacturing of continuous carbon fiber reinforced silicon carbide ceramic composite parts in the future.