颗粒级配对黏结剂喷射打印碳化硅陶瓷性能的影响

Effect of Particle Grading on Properties of Silicon Carbide Ceramics by Binder Jetting Printing

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20μm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/cm^(3),(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。

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 20μm.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/cm^(3),(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.