Key Takeaways & Executive Findings
- •• Additive manufacturing enables mold-free fabrication of complex soluble ceramic cores, reducing production time and cost. • Soluble ceramic cores, particularly water-soluble types, address the challenge of removing complex blind cavities in castings. • Various AM technologies (SL, SLS, DIW, BJ) have been successfully applied, each with distinct advantages and limitations. • Future developments focus on improving strength, surface quality, and expanding material options for soluble ceramic cores.
Abstract
Ceramic cores are key components in the production of castings with complex cavity structures. With the continuous development of the aerospace field, the demand for the castings with complex cavity structures is increasing. When using insoluble ceramic cores for casting, there is a significant challenge in removing complex blind cavities, which severely affects the completeness of the shape of the castings. Soluble ceramic cores can disintegrate when placed in water, greatly simplifying the removal process of cores and ensuring the complete formation of castings with complex cavity structures. Additive manufacturing technology, compared to traditional methods for preparing the soluble ceramic cores, does not require molds and can achieve direct forming of complex cores, simplifying the preparation process and reducing production time and costs. Nowadays, various additive manufacturing technologies, such as stereolithography (SL), selective laser sintering (SLS), direct ink writing (DIW), and binder jetting (BJ) technologies, have been successfully applied to the preparation of the ceramic cores. This paper analyzed the advantages and limitations of various additive manufacturing technologies, reviewed the research progress and raw material classifications of soluble ceramic cores prepared by these technologies, and looked forward to the future developments in the preparation of soluble ceramic cores using additive manufacturing technologies.
1. Introduction
With the rapid development of industries, notably aerospace, the demand for castings like engine casings and turbine blades has sharply increased, thereby placing higher performance requirements on these components [1-3]. These castings typically feature complex cavities and hollow thin-walled structures, along with slender bends and hidden slots, necessitating the use of cores during the casting process [4-6]. Traditional core forming processes, such as injection molding, isostatic pressing, and gel injection molding, require molds for preparation of the cores, leading to long production cycles and low efficiency [7, 8]. They also have significant limitations when forming large and complex structural cores.
Additionally, the cores prepared by traditional materials such as Al2O3 and SiO2 need to be removed by mechanical vibration, alkali corrosion, or other methods. These processes are challenging to achieve ideal results on cores within internal bending channels, and the lye can cause surface corrosion on the castings, affecting their quality. This significantly restricts the application of ceramic cores in casting production [9-13]. To address the issue of difficult core removal, water-soluble cores have been gradually introduced into casting production. The water-soluble cores mainly include water-soluble salt cores and water-soluble ceramic cores [14, 15]. The water-soluble salt cores can be removed through dissolution, achieving ideal removal effects. However, their low strength and high brittleness limit their applications [16, 17]. Although the water-soluble ceramic cores, such as CaO-based ceramic cores, have good performance and are easy to remove, CaO is prone to absorbing water and dehydrating, causing significant issues in core preparation and storage. This also restricts the further application of water-soluble CaO ceramic cores in casting production. Calcium carbonate (CaCO3) comes from a wide range of sources and is decomposed into CaO at high temperatures. Ceramic cores prepared using CaCO3 as raw materials exhibit good collapsibility after sintering, but relatively few research works can be found in related aspects.
In recent years, the rapid development of additive manufacturing technologies has provided new avenues for the preparation of complex cores [18-21]. Additive manufacturing is an advanced manufacturing method that uses a computer to slice a three-dimensional model of a part and then prints the part by depositing materials layer by layer [22-24]. Compared to traditional techniques, the additive manufacturing offers numerous advantages such as high customization, short production cycles, and the ability to produce parts with complex geometries [25-30]. Additive manufacturing technology does not need mold, can realize the direct forming of complex core, simplify the preparation process, reduce the production time and cost [31-36], these advantages position additive manufacturing technology as increasingly crucial in the field of ...
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Xiao-peng Yu, Wen-ming Jiang, Yun-xia Wang, Li Yang, Zi-wei Peng, Zi-tian Fan (2025). Preparation of soluble ceramic cores via additive manufacturing technology: A review. China Foundry. https://doi.org/10.1007/s41230-025-4210-2
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Frequently Asked Questions
What are soluble ceramic cores and why are they important?
Soluble ceramic cores are sacrificial components used in casting to create complex internal cavities. They can be dissolved in water, simplifying removal and ensuring complete formation of castings with complex structures.
How does additive manufacturing benefit the production of soluble ceramic cores?
Additive manufacturing eliminates the need for molds, enabling direct fabrication of complex cores, reducing production time and cost, and allowing high customization.
Which additive manufacturing technologies are used for soluble ceramic cores?
Technologies include stereolithography (SL), selective laser sintering (SLS), direct ink writing (DIW), and binder jetting (BJ).
What are the main challenges in using soluble ceramic cores?
Challenges include achieving adequate strength and surface quality, managing material properties like hygroscopicity, and optimizing removal processes.
What future developments are expected in this field?
Future work aims to improve mechanical properties, surface finish, and expand material options, as well as integrate multi-material printing and process optimization.
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