Silica-based ceramic cores for high-pressure turbine airfoil blades in aircraft engines

Autor: Gromada Magdalena, Tłuczek Agata, Cygan Rafał
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Processing and Application of Ceramics, Vol 18, Iss 3, Pp 299-306 (2024)
Druh dokumentu: article
ISSN: 1820-6131
2406-1034
DOI: 10.2298/PAC2403299G
Popis: Ceramic cores for high-pressure turbine airfoil blades in aircraft engines are characterised by very complicated shapes and the presence of small diameter holes and thin long grooves. In this paper, eight starting powder mixtures having different contents of fused silica, zirconium silicate, alumina and borosilicate glass were used for preparation of core material. The composition, which satisfies every demand for core application in the investment casting of high-pressure turbine blades, contains 69.0wt.% fused silica, 13.0 wt.% zirconium silicate, 12.0wt.% alumina and 6.0wt.% borosilicate glass. This material was characterised by a mechanical strength of 33.1MPa, a coefficient of thermal expansion of 2.56 × 10−6 1/K, surface roughness of 1.8 μm, shrinkage of less than 0.8% and an average pore size diameter of 2.7 μm. The thin-walled ceramic cores were formed by the high-pressure injection moulding method, which required the selection of a thermoplasticiser, feedstock formulation and determination of the optimal processing conditions protecting the injected cores from defects and deformation. The post-shaping process of the cores included both water and thermal debinding, sintering, precision machining and dimension measurements.
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