Creep behavior of silica bar core during directional solidification process of single crystal superalloy

Autor: JIANG Weiguo, HAN Dongyu, DONG Lin, LI Kaiwen, ZHAO Debiao, WANG Ruichun, REN Yuyan, LI Qiang, LI Yanzhao
Jazyk: čínština
Rok vydání: 2022
Předmět:
Zdroj: Journal of Aeronautical Materials, Vol 42, Iss 6, Pp 57-64 (2022)
Druh dokumentu: article
ISSN: 1005-5053
DOI: 10.11868/j.issn.1005-5053.2022.000057
Popis: Creep characterization of different diameter silica bar core during directional solidification of the single crystal superalloy was investigated by suspension method. The scanning electron microscope (SEM) was employed to observe the microstructure of the surface and transversal section of crept silica bar. The energy dispersive spectroscopy (EDS) and X-ray diffraction technology were used to analyse and determine the composition of the reaction product. The experimental results show that the crept deformation amount increases with prolonging of creep time and decreasing of the diameter of the silica bar. When the creep time is 60 min, the diameter 0.5 mm silica bar has the largest creep deformation, and the average deformation is 30 mm, while the 2 mm silica bar is 24 mm. The interfacial reaction of SiO2 with C and Al, which are deposited on the silica bar surface due to the elevated temperature and low vacuum, induces the formation of porous layer. The volume fraction of the porous reaction products leads to the different crept deformation amount of different diameter silica bars. The creep deformation amount of silica bars has a linear relationship with the volume fraction of surface reaction products.
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