Abstract
High-temperature oxidation behavior of conventionally cast and additively manufactured (AM) Co-base alloy MAR-M-509 was compared in the present study. The specimens were exposed in air at 1000 °C and characterized by means of scanning electron microscopy equipped with energy/wavelength dispersive x-ray spectroscopy (EDX/WDX) and electron backscatter diffraction as well as transmission electron microscopy. Substantial differences in the oxidation processes of two alloy versions were observed. Faster oxidation of the cast alloy was mainly induced by (1) oxidation of coarse primary carbides, (2) internal oxidation and nitridation processes and (3) incorporation of other alloy constituents (e.g., Co, Ni, W) into the Cr-oxide scale. AM specimens, in contrast, formed a more homogeneous, thinner and better adherent external oxide scale. The results are discussed in terms of differences in the chemical composition and alloy microstructure, including the grain size distribution in the material and the morphology of the strengthening precipitate phases.
| Original language | English |
|---|---|
| Pages (from-to) | 791-816 |
| Number of pages | 26 |
| Journal | High Temperature Corrosion of Materials |
| Volume | 100 |
| Issue number | 5-6 |
| DOIs | |
| State | Published - Dec 2023 |
Funding
The authors are grateful to Dr. R. Herzog and Mr. M. Ernsberger from MAN Energy Solutions SE for providing Co-base materials for the present study. Following colleagues in the Institute for Energy and Climate Research of the Forschungszentrum Jülich GmbH are greatly acknowledged: Mr. H. Cosler and Ms. A. Kick for carrying out the high-temperature exposures, Dr. E. Wessel and Dr. D. Grüner for SEM/EDX/EBSD and TEM analyses, and Mr. M. Ziegner for XRD analyses. Open Access funding enabled and organized by Projekt DEAL. The study was funded by the Forschungszentrum Juelich GmbH (internal funding).
Keywords
- Additive manufacturing
- Co-base alloys
- High-temperature oxidation
- MAR-M-509
- Selective laser melting
