Innovative Brazing of Ti6Al4V and Inconel 718 Alloys Using Cobalt Coated BNi-2 Powders

Date

2025-9-1

Author

Göynük, Tansu

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

203
views

0
downloads

Cite This

The structural integration of dissimilar alloys such as Ti6Al4V and Inconel 718 presents considerable difficulties in high-performance applications due to their different melting ranges, chemical compositions, and thermal expansion behaviors. Brazing stands out as a viable solution for joining these alloys both among themselves and with each other without compromising their individual properties. This study explores advanced brazing strategies by employing BNi-2 as the filler metal and enhancing its performance through compositional modification. In particular, cobalt was incorporated onto the surface of BNi-2 powders via an electroless deposition process in order to promote superior interfacial bonding and thermal stability during joining. A wide-ranging experimental procedure was carried out, including vacuum brazing trials, wetting experiments, molecular modelling, diffusion analysis, and mechanical testing of joints. These were supported by multiscale characterization techniques such as scanning electron microscopy, X-ray diffraction, microhardness evaluation, and fractographic analysis, as well as atomistic simulations using molecular dynamics to understand interfacial phenomena at the nanoscale. The integration of electroless cobalt coating and computational modeling provided critical insights into the relationship between filler alloy chemistry and joint integrity. The results demonstrate that the coated BNi-2 alloy exhibits significantly improved wetting behavior and diffusion compatibility with both base metals, leading to stronger and more reliable joints under high-temperature service conditions. The findings of this research offer valuable contributions to the development of next-generation brazing solutions for similar and dissimilar metal systems used in aerospace and other demanding engineering environments.

Subject Keywords

Vacuum Brazing, Ti-6Al-4V, Inconel 718, Electroless Cobalt Coating, Molecular Dynamics Simulation

URI

https://hdl.handle.net/11511/116122

Collections

Graduate School of Natural and Applied Sciences, Thesis