3D printing of silica-based ceramic cores reinforced by alumina with controlled anisotropy
Ceramic core (CC) is a key component in the casting of aero-engine turbine blades, and CC through 3D printing is crucial to the growing aviation technology. However, these silica CCs are highly limited by their high temperature softening and inevitable anisotropy. In this work, silica-based CCs rein...
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Veröffentlicht in: | Journal of alloys and compounds 2022-11, Vol.922, p.166325, Article 166325 |
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Sprache: | eng |
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Zusammenfassung: | Ceramic core (CC) is a key component in the casting of aero-engine turbine blades, and CC through 3D printing is crucial to the growing aviation technology. However, these silica CCs are highly limited by their high temperature softening and inevitable anisotropy. In this work, silica-based CCs reinforced by alumina powders are manufactured by 3D printing via digital light processing (DLP) stereolithography, and the anisotropy in microstructure and property was investigated. In the CC without alumina powders, multilayer structures with significant interlayer gaps are exhibited in horizontal printing direction suggesting significant anisotropy in microstructure, which is related to the particle deposition in printing. As the alumina content is 6 wt%, microstructures become uniform, due to the enhanced particle rearrangement between different layers. To assess the mechanical anisotropy, the ratio of vertical strength to horizontal strength (σV/σH) is raised, and the σV/σH ratios rise from 0.45 to 0.86 at room temperature and 0.52–0.89 at 1540 °C with increasing alumina content from 0 to 6 wt%. As the alumina content is 6 wt%, the CC exhibits high temperature flexure strengths as high as 17.9 MPa and 19.5 MPa in different directions, well satisfying the demands for turbine blades casting. This article inspires a profound understanding on the anisotropy control in 3D printing of CC with excellent high-temperature mechanical properties.
•3D printed Ceramic cores exhibit anisotropy in structure and mechanical property.•The microstructure anisotropy is featured by multilayer structures with interlayer gaps.•The mechanical anisotropy is assessed through the ratio of vertical strength to horizontal strength (σV/σH).•Moderate contents of alumina powders promote the uniformity in microstructure and high temperature mechanical property with σV/σH of 0.89. |
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ISSN: | 0925-8388 1873-4669 |
DOI: | 10.1016/j.jallcom.2022.166325 |