Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam Melting
In this work, the microstructures of superalloy specimens produced using selective electron beam melting additive manufacturing were characterized. The materials were produced using a CMSX-4 powder. Two selective electron beam melting processing strategies, which result in higher and lower effective...
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MDPI AG
2016-10-01
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| Series: | Metals |
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| Online Access: | http://www.mdpi.com/2075-4701/6/11/258 |
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| author | Alireza B. Parsa Markus Ramsperger Aleksander Kostka Christoph Somsen Carolin Körner Gunther Eggeler |
| author_facet | Alireza B. Parsa Markus Ramsperger Aleksander Kostka Christoph Somsen Carolin Körner Gunther Eggeler |
| author_sort | Alireza B. Parsa |
| collection | DOAJ |
| description | In this work, the microstructures of superalloy specimens produced using selective electron beam melting additive manufacturing were characterized. The materials were produced using a CMSX-4 powder. Two selective electron beam melting processing strategies, which result in higher and lower effective cooling rates, are described. Orientation imaging microscopy, scanning transmission electron microscopy and conventional high resolution transmission electron microscopy are used to investigate the microstructures. Our results suggest that selective electron beam melting processing results in near equilibrium microstructures, as far as γ′ volume fractions, the formation of small amounts of TCP phases and the partitioning behavior of the alloy elements are concerned. As expected, higher cooling rates result in smaller dendrite spacings, which are two orders of magnitude smaller than observed during conventional single crystal casting. During processing, columnar grains grow in <100> directions, which are rotated with respect to each other. There are coarse γ/γ′ microstructures in high angle boundary regions. Dislocation networks form low angle boundaries. A striking feature of the as processed selective electron beam melting specimens is their high dislocation density. From a fundamental point of view, this opens new possibilities for the investigation of elementary dislocation processes which accompany solidification. |
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| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-20T23:04:11Z |
| publishDate | 2016-10-01 |
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| spelling | doaj.art-13f7fc7083214e6992df67f49fd7dfd72022-12-21T19:23:54ZengMDPI AGMetals2075-47012016-10-0161125810.3390/met6110258met6110258Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam MeltingAlireza B. Parsa0Markus Ramsperger1Aleksander Kostka2Christoph Somsen3Carolin Körner4Gunther Eggeler5Institut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, Bochum 44801, GermanyLehrstuhl WTM, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstr. 5, Erlangen 91058, GermanyInstitut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, Bochum 44801, GermanyInstitut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, Bochum 44801, GermanyLehrstuhl WTM, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstr. 5, Erlangen 91058, GermanyInstitut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, Bochum 44801, GermanyIn this work, the microstructures of superalloy specimens produced using selective electron beam melting additive manufacturing were characterized. The materials were produced using a CMSX-4 powder. Two selective electron beam melting processing strategies, which result in higher and lower effective cooling rates, are described. Orientation imaging microscopy, scanning transmission electron microscopy and conventional high resolution transmission electron microscopy are used to investigate the microstructures. Our results suggest that selective electron beam melting processing results in near equilibrium microstructures, as far as γ′ volume fractions, the formation of small amounts of TCP phases and the partitioning behavior of the alloy elements are concerned. As expected, higher cooling rates result in smaller dendrite spacings, which are two orders of magnitude smaller than observed during conventional single crystal casting. During processing, columnar grains grow in <100> directions, which are rotated with respect to each other. There are coarse γ/γ′ microstructures in high angle boundary regions. Dislocation networks form low angle boundaries. A striking feature of the as processed selective electron beam melting specimens is their high dislocation density. From a fundamental point of view, this opens new possibilities for the investigation of elementary dislocation processes which accompany solidification.http://www.mdpi.com/2075-4701/6/11/258Ni-base superalloyselective electron beam meltingevolution of microstructuretransmission electron microscopyingrown dislocations |
| spellingShingle | Alireza B. Parsa Markus Ramsperger Aleksander Kostka Christoph Somsen Carolin Körner Gunther Eggeler Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam Melting Metals Ni-base superalloy selective electron beam melting evolution of microstructure transmission electron microscopy ingrown dislocations |
| title | Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam Melting |
| title_full | Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam Melting |
| title_fullStr | Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam Melting |
| title_full_unstemmed | Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam Melting |
| title_short | Transmission Electron Microscopy of a CMSX-4 Ni-Base Superalloy Produced by Selective Electron Beam Melting |
| title_sort | transmission electron microscopy of a cmsx 4 ni base superalloy produced by selective electron beam melting |
| topic | Ni-base superalloy selective electron beam melting evolution of microstructure transmission electron microscopy ingrown dislocations |
| url | http://www.mdpi.com/2075-4701/6/11/258 |
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