【摘要】 采用直写成型反应熔渗工艺制备了SiCnf/SiC复合陶瓷。通过SiC颗粒、炭黑、SiCnf、海藻酸钠、聚乙二醇等原料的组分设计制备了流变性能满足直写成型要求的陶瓷浆料,然后经过直写成型、干燥、脱脂排胶和酚醛树脂浸渍裂解,最后通过反应熔渗进行致密化烧结,得到SiCnf/SiC复合陶瓷材料。研究了炭黑与SiCnf添加量对SiC陶瓷材料组织演变、相组成和力学性能的影响。结果表明,当炭黑添加量为2vol.%时,SiC陶瓷的弯曲强度达到最大为236.3MPa。当SiCnf添加量为4vol.%时,SiCnf/SiC复合陶瓷材料的弯曲强度和断裂韧性均达到最大值,分别为279.8 MPa和4.26 MPa·m^1/2,其与未添加SiCnf的试样相比,分别提高了18.5%和22.4%。该工艺在制备具有异形结构的陶瓷构件方面具有广泛的应用。更多还原

【Abstract】 The SiCnf/SiC composites were fabricated by combination of direct ink writing and reactive melt infiltration.By designing the component of the raw materials,the SiC particles,carbon black,SiCnf,sodium alginate and polyethylene glyclo were used as raw materials to prepare the ceramic slurry with appropriate rheological properties that could meet the requirements of direct ink writing technology.After direct ink writing,drying,debinding,phenolic resin impregnation and pyrolysis,and finally densification and sintering by reactive melt infiltration,SiCnf/SiC composite ceramics were obtained.Effects of additive content of the carbon black and the SiCnf on microstructure evolution,phase composition and mechanical properties of SiC ceramic materials were analyzed in detail.The results showed that the flexural strength of SiC ceramics reached a maximum of 236.3 MPa when the content of carbon black was 2 vol.%.And,the flexural strength and fracture toughness of SiCnf/SiC composites reached the maximum values of 279.8 MPa and 4.26MPa·ml/2 respectively,when the content of SiCnf was 4 vol.%.Compared to the samples without the SiCnf,the flexural strength and fracture toughness were increased by 18.5% and 22.4%respectively.This method exhibited great application prospects in manufacturing ceramic co mponents with co mplex structures.更多还原