Original scientific paper

Microstructural characteristics of new type γ-γ` Co-9Al-9W cobalt-based superalloys in as-cast state

A. Tomaszewska ; Silesian University of Technology, Katowice, Poland
B. Oleksiak orcid.org/0000-0001-6038-4251 ; Silesian University of Technology, Katowice, Poland

Abstract

The paper presented deals primary with the structure characteristics of a new type of cobalt-based superalloys Co-9Al-9W type, casted via induction melting process with partially dosing of Common problems described in literature are focused on difficulties in obtaining uniform distribution of tungsten, particularly in interdendritic areas. That was the reason for the modified casting process to be applied. The method of tungsten dosing into liquid melts of Co and Al allows to obtain microstructure characterized by considerably decreased microsegregation. The material obtained was analyzed by standard methods such as light and scanning microscopy with analysis of chemical composition in micro-areas. Additionally, the detailed analysis of the sub-grain level was made by S/TEM on thin foils collected from equiaxed grains zone of the ingot.

Keywords

Co-9Al-9W alloy; casting process; primary microstructure; Scanning Electron Microscopy (SEM) analysis; Scanning Transmission Electron Microscopy (STEM) analysis

Hrčak ID:

189372

URI

https://hrcak.srce.hr/189372

Publication date:

1.1.2018.

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