碳化硅(SiC)陶瓷作为一种高性能结构功能一体化的陶瓷材料, 在航空航天、核能工业和制动系统等领域应用广泛。然而, 传统的制造方法无法满足大尺寸复杂结构SiC陶瓷日益增长的市场需求, 例如发动机喷嘴、襟翼和涡轮叶片等。黏结剂喷射(BJ)3D打印突破了传统成型的约束, 可以提供新的制造思路。本工作采用颗粒级配SiC的思路, 基于级配理论优化较佳的颗粒度配比, 研究了BJ打印对级配前后SiC陶瓷素坯及烧结体性能的影响。研究发现, BJ打印级配后的SiC素坯经过一次前驱体浸渍裂解(PIP)处理, 能够快速制备抗弯强度最大达到(16.70± 0.53) MPa的SiC素坯, 相比采用20 μm中位径未级配的样品提高了116%。进一步采用液相渗硅制备了致密的SiC陶瓷, 其密度、抗弯强度、弹性模量和断裂韧性分别达到(2.655±0.001) g/cm³, (285±30) MPa, (243±12) GPa和(2.54±0.02) MPa·m^1/2。XRD分析表明, SiC烧结体主要以3C-β-SiC晶为主。本研究基于颗粒级配的原料, 采用黏结剂喷射打印, 结合一次浸渍裂解与液相渗硅制备工艺, 高效可靠地制备了高性能SiC陶瓷材料。

In this work, carbon fiber and polyaniline (CF|PANI) composites are prepared by using an electrochemical polymerization method. The morphology and composition characterization results show that the PANI nanospheres are successfully synthesized and uniformly coated on the CF. When the electrodeposition period is 300 cycles, the as-prepared CF|PANI electrode exhibits good specific capacitance of 231.63 F/g at 1 A/g, high performance of 98.14% retention rate from 0.5 to 20 A/g, and excellent cycle stability with only 0.96% capacity loss after 1000 cycles. This is ascribed to the internal resistance that was significantly reduced without binders, which helps to the CF|PANI electrode maintains high operating potential and pseudo-capacitance performance at high current density. The symmetrical supercapacitor based on two CF|PANI electrodes connecting by acidic PVA-H₂SO₄ gel electrolyte exhibits an energy density of 6.55 W·h/kg at a power density of 564.37 W/kg. In addition, the asymmetric supercapacitor based on MoS₂|MWCNTs and CF|PANI electrodes with neutral PVA-Na₂SO₄ gel electrolyte shows an energy density of 16.12 W·h/kg at a power density of 525.03 W/kg. These results indicate that the low internal resistance contributes to the high energy density of symmetrical supercapacitors and asymmetric supercapacitors at high current density and high power density, which is significant for its practical application.In this work, carbon fiber and polyaniline (CF|PANI) composites are prepared by using an electrochemical polymerization method. The morphology and composition characterization results show that the PANI nanospheres are successfully synthesized and uniformly coated on the CF. When the electrodeposition period is 300 cycles, the as-prepared CF|PANI electrode exhibits good specific capacitance of 231.63 F/g at 1 A/g, high performance of 98.14% retention rate from 0.5 to 20 A/g, and excellent cycle stability with only 0.96% capacity loss after 1000 cycles. This is ascribed to the internal resistance that was significantly reduced without binders, which helps to the CF|PANI electrode maintains high operating potential and pseudo-capacitance performance at high current density. The symmetrical supercapacitor based on two CF|PANI electrodes connecting by acidic PVA-H₂SO₄ gel electrolyte exhibits an energy density of 6.55 W·h/kg at a power density of 564.37 W/kg. In addition, the asymmetric supercapacitor based on MoS₂|MWCNTs and CF|PANI electrodes with neutral PVA-Na₂SO₄ gel electrolyte shows an energy density of 16.12 W·h/kg at a power density of 525.03 W/kg. These results indicate that the low internal resistance contributes to the high energy density of symmetrical supercapacitors and asymmetric supercapacitors at high current density and high power density, which is significant for its practical application.