Research progress on 3D printing and anisotropy of ceramic cores for hollow blade casting

As an emerging moulding technology, 3D printing has steadily matured and is poised to supplant the traditional hot-press injection moulding technology, emerging as a pivotal approach for manufacturing ceramic cores in aerospace turbine blades. Nevertheless, 3D-printed ceramic cores produced through 3D printing display significant anisotropy in mechanical properties, including sintering shrinkage rate and strength, owing to their layered structure and directionally arranged porosity. This anisotropic characteristic severely impedes their manufacturing potential and application scope, posing a critical challenge that demands urgent resolution. This paper offers a systematic summary of the manifestations of anisotropy in 3D-printed ceramic cores, clarifies the underlying formation mechanisms, formulates evaluation criteria, and puts forward effective control strategies. Additionally, it delineates future research directions, encompassing material system innovation, process optimization, comprehensive property regulation, multi-technology integration, and intelligent manufacturing methods. These endeavors lay a solid theoretical groundwork for promoting the high-performance realization and large-scale application of 3D-printed ceramic cores.