The performance of a newly developed multiprincipal-element alloy (MPEA) filler metal for brazing of nickel-based superalloys was directly compared to a conventional boron- and silicon-suppressed filler (BSSF) metal. The comparison was demonstrated on an Alloy 600 substrate with a brazing temperature of 1200°C. Single-phase solidification behavior and the absence of boron and silicon in the MPEA led to a joint microstructure devoid of eutectic constituents or brittle phases in brazes employing this filler metal. In the brazes using the conventional BSSF metal, incomplete isothermal solidification and subsequent athermal solidification of the residual liquid resulted in large particles of a chromium-rich boride phase distributed throughout the microstructure. Tensile testing of brazed butt joints at both room temperature and 600°C testing conditions demonstrated that the MPEA joints exhibited total ductility values at least one order of magnitude greater than that of BSSF joints, but they showed comparable yield strengths in both testing conditions. Fractographic assessment confirmed that boride phases nucleated cracks and resulted in brittle failure in the BSSF joints, while the MPEA joints exhibited extensive ductile microvoid coalescence. Fine-scale porosity and oxide inclusions may be the dominant factors limiting the overall ductility observed in the MPEA brazes.
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Compositionally Complex Alloy MnFeCoNiCu for Brazing Nickel‐Based Superalloy Haynes 214
The microstructural and mechanical properties of a MnFeCoNiCu braze filler are analyzed and compared to a conventional nickel‐based braze filler alloy on Haynes 214 as the base material. Tensile tests reveal that the samples brazed with the MnFeCoNiCu compositionally complex alloy (CCA) exhibit superior ductility increased by a factor of 1.6 compared to those brazed with the nickel‐based filler. The ultimate tensile strength remains comparable (factor 1.03). Contact angles recorded during the brazing process indicate comparable wetting properties between the two fillers. Based on experimental investigations and Thermo–Calc predictions, improved brazing parameters are proposed for the CCA filler on Haynes 214. These recommendations include lower brazing temperatures, shortened holding times, and faster cooling rates.
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- Award ID(s):
- 1847630
- PAR ID:
- 10515082
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Engineering Materials
- Volume:
- 26
- Issue:
- 14
- ISSN:
- 1438-1656
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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