About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials and Chemistry for Molten Salt Systems
|
| Presentation Title |
Engineering Grain Boundaries of Ni-Based Alloys Against Intergranular Molten Chloride Corrosion |
| Author(s) |
Sangtae Kim, Ho-A Kim, Zihan Lin, Ho Lee, Seongwon Ham, Tyler Dolezal, Emre Tekoglu, Ju Li |
| On-Site Speaker (Planned) |
Sangtae Kim |
| Abstract Scope |
Grain boundary strengthening with Mo-rich boride precipitates is shown to markedly improve the resistance of Ni-based alloys to intergranular attack in molten chlorides. Metal-matrix composites of Inconel 625 containing 2wt% TiB₂ or ZrB₂ were fabricated by laser powder-bed fusion and exposed for 300 h to NaCl–KCl–MgCl₂ at 800°C. The unmodified alloys exhibited maximum chromium-depletion depths of 71.3 µm, whereas TiB₂- and ZrB₂-reinforced alloys showed the depths notably reduced to 12.5 µm and 47.9 µm, respectively. SEM/EDS analyses combined with CALPHAD calculations confirmed the formation of Mo-rich boride precipitates along grain boundaries in the boride-modified materials. Pourbaix-diagram calculations indicate that these borides are thermodynamically stable in molten chlorides, thereby shielding grain boundaries from corrosion. The superior performance of the TiB₂ composite is attributed to the increased mole fraction of the protective borides. These findings provide a practical design strategy for Ni-based alloys with enhanced resistance to intergranular molten-salt corrosion. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Additive Manufacturing, Environmental Effects |