About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Bulk Metallic Glasses XX
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Presentation Title |
Atomic-scale Nature of the Invar Effect in Fe-based Bulk Metallic Glasses |
Author(s) |
Alexander Firlus, Mihai Stoica, Stefan Michalik, Gavin Vaughan, Robin E Schäublin, Jörg F Löffler |
On-Site Speaker (Planned) |
Alexander Firlus |
Abstract Scope |
Fe-based bulk metallic glasses (BMGs) universally show an anomalously low coefficient of thermal expansion below their Curie temperature. This effect is known as Invar effect. It is well known at the macroscopic scale but its atomic origins are little understood. There is agreement that it is a magnetic effect, but the role of the atomic species and the impact of the disordered atomic arrangement on the universality of the Invar effect is unknown.
In this work we studied the thermal expansion at the atomic scale by in-situ X-ray diffraction on multiple quaternary BMGs. All these BMGs show a reduced thermal expansion of the interatomic distances below the Curie temperature. Through variation of the minor alloying elements the origin of the Invar effect can be attributed to the disordered Fe network. Together with atomic-scale dilatometry measurements on multiple BMGs, we present our improved understanding of the Invar effect in amorphous materials. |
Proceedings Inclusion? |
Planned: |
Keywords |
Magnetic Materials, Other, Other |