Formation of abnormal structure in ZTA15 titanium alloy casting and its impact mechanism on tensile behavior

Partial block-dropping phenomenon was existed during the precision process of TA15 titanium alloy casting. In view of multiple means of microscopic physical characterization analysis such as OM/SEM/EDS/XRD and by considering the tensile performance results, the microstructure and mechanical properti...

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Bibliographic Details
Main Authors: LIU Gaoyang, ZHAO Wenxia, WANG Xi
Format: Article
Language:zho
Published: Journal of Aeronautical Materials 2020-08-01
Series:Journal of Aeronautical Materials
Subjects:
Online Access:http://jam.biam.ac.cn/article/doi/10.11868/j.issn.1005-5053.2020.000060
Description
Summary:Partial block-dropping phenomenon was existed during the precision process of TA15 titanium alloy casting. In view of multiple means of microscopic physical characterization analysis such as OM/SEM/EDS/XRD and by considering the tensile performance results, the microstructure and mechanical properties between block-dropping area and the regular areahad been investigated. This article focused on the impact mechanism on tensile behavior that generated from the abnormal structure of block-dropping area. The results reveal that both the block-dropping area and the regular area show bi-modal microstructure, whereas the β phase concentration of the block-dropping area is far beyond the regular area and emerges as β spot. Microanalysis shows that the segregation of Fe is the major factor causing the abnormal structure and β spot, as well as the sharp plasticity decreases of alloy. The segregated Fe alters the microstructure and properties of the alloy, mainly because the saturation of Fe in α-Ti is only 0.1%, which leads to the formation of brittle TiFe eutectic phase. The increase of strength reduces the plasticity of the alloy casting, and further lead to the block-dropping during the process.
ISSN:1005-5053
1005-5053