About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
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Symposium
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Additive Manufacturing and Alloy Design: Bridging Fundamental Physical Metallurgy, Advanced Characterization Techniques, and Integrated Computational Materials Engineering for Advanced Materials
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Presentation Title |
Towards Successful Additive Manufacturing of NiMnGa Magnetic Shape Memory Alloys: Laser Surface Remelting |
Author(s) |
Ali Ramezannejad, Daniel East, Kun Yang |
On-Site Speaker (Planned) |
Ali Ramezannejad |
Abstract Scope |
Laser surface remelting was employed to investigate the impact of varying the energy density on the microstructure, mechanical properties and twin boundary mobility of polycrystalline NiMnGa magnetic shape memory alloys. X-ray and electron backscatter diffraction analyses indicated that varying the energy density influences the stability, texture and lattice commensuration of 5M and 7M martensite phases, differently. Additionally, the long-sought-for control over the 5M twin type was realised for the first time, through careful control of process parameters. However, contrary to conventional belief, Type II twins did not necessarily exhibit a greater twin boundary mobility within single crystals. Significant lattice defects were identified via high-resolution transmission electron microscopy (TEM), as the underlying mechanism leading to the unexpected sluggish Type II twin boundary motion. Similarly, in-situ TEM experiments were conducted to understand the influence of these defects on the forward and reverse martensitic transformations within the remelted tracks. |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, Phase Transformations, Magnetic Materials |