About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Metal Matrix Composites: Processing, Additive Manufacturing, and Applications
|
| Presentation Title |
Microstructural control of hydrogen transport and deformation mechanisms in LPBF-fabricated nanoparticle-reinforced CoCrFeNi composites |
| Author(s) |
Vivek Devulapalli, Gerhard Dehm, Eric A Jaegle, Marc Legros, Johann Michler, Xavier Maeder |
| On-Site Speaker (Planned) |
Vivek Devulapalli |
| Abstract Scope |
This presentation examines the design, processing, and deformation behavior of nanoparticle-reinforced CoCrFeNi medium-entropy alloy metal matrix composites fabricated by laser powder bed fusion (LPBF). Through the incorporation of TiN and TiO2 feedstock additions, LPBF processing was used to tailor solidification behavior, grain morphology, and the formation of a homogeneous dispersion of nanoscale oxide reinforcements, resulting in enhanced strength and hardness. Building on this microstructural framework, the work investigates the response of these additively manufactured nanocomposites to hydrogen exposure using nanoindentation, thermal desorption spectroscopy, and advanced electron microscopy. Hydrogen-induced softening is correlated with grain morphology, hydrogen transport pathways, stacking-fault formation, deformation twinning, and dislocation-mediated plasticity, revealing how microstructural architecture governs environmental degradation. Furthermore, in situ transmission electron microscopy tensile testing performed at both room and cryogenic temperatures provides direct observations of defect evolution, nanoparticle–dislocation interactions, and active deformation mechanisms under applied stress. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Additive Manufacturing, Mechanical Properties |