About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
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Symposium
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Alloy Phase Transformations at Elevated Temperatures
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Presentation Title |
Microstructure Evolution and Mechanical Properties of α′/α″-Strengthened Ferritic Superalloys |
Author(s) |
Christopher H. Zenk, Luis Morales, Andreas Bezold, Andreas Förner, Steffen Neumeier, Carolin Körner |
On-Site Speaker (Planned) |
Christopher H. Zenk |
Abstract Scope |
Ferritic superalloys are an emerging class of materials based on the Fe-Al-Ni system. A coherent bcc-derived α/α′ (A2/B2) microstructure can be established, analogous to the γ/γ′ (A1/L12) microstructure of Ni-base superalloys. With Fe as their base element (∼50at.%) and a high Al-content (∼18at.%) these materials have a major cost advantage over Ni-base superalloys. The addition of Ti facilitates the partial transformation of α′ into L21 (based on Ni2AlTi, henceforth α″) and significantly improves the creep resistance of these alloys. Our alloy development efforts led to an α′/α″-strengthened alloy that was additively manufactured via Laser Metal Deposition. In-situ synchrotron diffraction reveals insights into the complex phase transformation pathway through which a variety of different microstructures can be designed. The elemental partitioning between the three phases is measured in TEM and APT. The high-temperature mechanical properties will be discussed on the basis of compressive and tensile tests as well as creep tests. |