Full
ZHOU Jiajie (2001-), male, Master candidate. E-mail: jiajiezhou2001@163.com
Outline
Ceramic molds, including cores for internal cavities and shells for outer contours, are essential components for precision casting of complex parts in aerospace, energy equipment, and medical devices, due to their excellent thermal stability, high strength, and dimensional accuracy. As high-end castings evolve toward lightweight and integrated designs, conventional mold-dependent methods such as injection molding and gel casting have limitations. These techniques require splicing for complex structures, leading to long development cycles, poor joint performance, and high costs. Powder bed additive manufacturing (PBAM), including binder jetting additive manufacturing (BJAM) and selective laser sintering (SLS), enables mold-free, rapid, and integral fabrication of complex ceramic molds, offering a pathway for efficient short-process manufacturing.
This review systematically summarizes recent development on BJAM and SLS for ceramic mold fabrication, focusing on the effects of powder materials and printing parameters on the mold performance, post-processing regulation methods, engineering applications, and future directions. In BJAM, ceramic molds are formed via selectively depositing a liquid binder onto powder layers. Powder properties including particle size distribution, flowability, and composition critically determine green density and sintered properties. Common materials like Al2O3 and CaO are widely used, but they require additives such as sintering aids (i.e., nano-sized Al2O3, CuO-TiO2) and shrinkage compensators (i.e., Al powder, and SiO2). Key printing parameters, particularly binder saturation and layer thickness, significantly affect the green strength and surface quality. Post-processing through sintering optimization and vacuum infiltration with silica sol or nano-sized additives is essential to achieve required mechanical properties and porosity. BJAM features a high efficiency, a broad material adaptability, and a support-free fabrication, making it suitable for large ceramic molds with complex internal structures. In SLS, ceramic molds are formed by high-energy laser selectively melting polymer-coated or binder-mixed ceramic powders without liquid binders, providing a higher green strength. The powder system comprises ceramic matrix materials (i.e., SiO2, Al2O3), organic or inorganic binders (i.e., phenolic resin, B4C), and functional additives to enhance flowability and laser absorption. Critical parameters like laser power, scanning speed, layer thickness, and hatch spacing determine energy input and part quality. Post-processing via sintering and infiltration is required to achieve high-temperature strength, creep resistance, and dimensional stability. SLS delivers green bodies with a high initial density, ideal for complex thin-walled molds and high-precision applications in directional solidification casting.
BJAM and SLS both are applied in producing ceramic cores and shells for turbine blades and impellers, demonstrating complex cooling passages, high surface finish, and excellent high-temperature performance that meet stringent casting requirements.
The existing PBAM achieves phased results. To further promote its large-scale application in the fabrication of high-performance ceramic molds, there are the following aspects. There is an urgent need to develop additive manufacturing-specific powders and functional binder systems. For BJAM process, composite ceramic powders with favorable flowability and optimized gradation should be developed, and multifunctional binder systems should be designed to reduce the dependence on post-processing performance regulation. For SLS process, it is necessary to develop ceramic/binder phase composite powders with high laser absorptivity and excellent sintering activity, so as to reduce the difficulty of subsequent sintering and improve the strength of ceramic molds. Dedicated printing systems and post-processing equipment suitable for the multi-material integrated forming of ceramic molds should be developed. Key technologies such as precise multi-material powder spreading and delivery, as well as synchronous manufacturing of ceramic cores and shells, should be prioritized to realize high-precision and high-efficiency integrated forming of ceramic molds with complex structures. Regarding the performance regulation, improving the high-temperature strength, creep resistance and dimensional stability of ceramic molds becomes an emphasis. The porosity and relative density can be synergistically regulated to balance the contradiction between high strength and easy core leaching by means of material design, printing parameter adjustment and post-processing process optimization, so as to meet the stringent performance requirements of ceramic molds for high-end castings.
4
1
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
