|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||2018 Technical Division Student Poster Competition
||SPU-8: Laser Brazing of Nickel Superalloys with a Ni-Mn-Fe-Co-Cu High Entropy Alloy Nanopaste
||Samantha Lang, Denzel Bridges, Anming Hu
|On-Site Speaker (Planned)
In this study, laser brazing was conducted with a nickel superalloy and Ni-Mn-Fe-Co-Cu high entropy alloy (HEA) nanopaste of molar ratio 1:1:1:0.25:1.75 to observe changes in mechanical performance, diffusion behavior, and microstructure evolution. HEA nanoparticles were formed by a top-down synthesis approach and condensed into paste. Shear strength testing of joints formed by brazing revealed the nanopaste gave similar mechanical properties to joints brazed with a bulk sample of the HEA, but with a lower temperature threshold. The nanopaste and bulk metal achieve maximum bonding strength near the liquidus temperature of the HEA. Far above this temperature, the strength suffers due to excessive diffusion of the filler and base metals.  Cr in the nanopaste was observed to migrate toward the base metal ahead of other constituents during diffusion, suggesting a phase change of the HEA contributes to the bonding strength.
 D. Bridges et al., Mater. Lett.(2017), doi: https://doi.org/10.1016/j.matlet.2017.12.003