颗粒级配对黏结剂喷射打印碳化硅陶瓷性能的影响

Silicon carbide (SiC) ceramics, as a high-performance structural-functional integrated material, are widely used in aerospace, nuclear industry and braking system. However, the conventional fabrication methods can not meet the increasing demands for large-scale and complex-structured SiC ceramics, such as engine nozzles, flaps and turbine blades. Binder jetting (BJ) 3D printing technology can overcome the traditional obstacle and provide a novel manufacturing roadmap. Here, we adopted this technique via SiC particle grading, optimized the particle size ratio based on gradation theory, and studied the influence of BJ printing on properties of SiC green body and as-sintered ceramic. For the particle-graded green body after BJ printing, SiC ceramics with a maximum flexural strength of (16.70±0.53) MPa was obtained after one precursor impregnation and pyrolysis (PIP) treatment, whose flexural strength was improved by 116% as compared with that BJ printed from a median diameter of 20 μm. SiC ceramics were further densified using liquid phase siliconization, with the density, flexural strength, elastic modulus, and fracture toughness reaching (2.655±0.001) g/cm³, (285±30) MPa, (243±12) GPa, and (2.54±0.02) MPa·m^1/2, respectively. XRD results demonstrated that the sintered SiC ceramics were mainly composed of 3C structured-β-SiC. All results show that high-performance SiC ceramic materials are innovatively prepared by an efficient and reliable method, based on the combined techniques of particle grading, BJ printing, PIP and liquid silicon infiltration.