About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Effect of Micro-segregation of Alloying Elements on the Precipitation Behaviour in Laser Surface Engineered Alloy 718 |
| Author(s) |
Srinivas Aditya Mantri, SriSwaroop Dasari, Abhishek Sharma, Mangesh Pantawane, Narendra Dahotre, Rajarshi Banerjee, Srikumar Banerjee |
| On-Site Speaker (Planned) |
Srinivas Aditya Mantri |
| Abstract Scope |
Micro-segregation of alloying elements in the fusion zone of laser surface melted Alloy 718 samples has been found to have a strong influence on the local precipitation behavior. The dendritic structure produced by rapid melting and solidification has shown three distinct zones – a) core and b) periphery of dendrites, and c) the inter-dendritic channel. While precipitation of γ’ dominates in the core, the periphery is decorated by γ” and composite γ’/γ” precipitates, all in the γ matrix. The inter-dendritic channel, rich in Nb, Mo, and C, contains discretized aggregates of Laves phase and carbides, which act as preferential nucleation sites for the equilibrium δ phase. Microscopic examinations at different length scales using SEM, site-specific TEM (both diffraction contrast and phase contrast) and APT have revealed several hitherto unknown features of precipitation processes in a compositionally inhomogeneous Alloy 718, which are invariably encountered in components produced by laser additive manufacturing. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Additive Manufacturing, Characterization |