Abstract: Inconel 718 is a popular precipitation-hardened, corrosion-resistant nickel superalloy that is widely used in aerospace turbines, liquid fueled rockets, and other high temperature applications. To better match the high temperature stability of Inconel 718, a MnCoCrNiFe high entropy alloy (HEA) bulk material and nanoparticle paste (nanopaste) were developed. Two brazing techniques were investigated for this brazing material: laser brazing and vacuum brazing. Laser brazing produces a small heat affected zone and very short brazing time. For vacuum brazing, transient liquid phase bonding is employed for brazing Inconel 718 to exploit a lower processing temperature by heating above the solidus line of HEA in conjunction with the size-dependent melting point depression behavior of nanoparticles. The mechanical properties and microstructural evolution of the brazed joints were determined to build a fundamental understanding of HEA brazing filler metals and the difference in behavior of the bulk brazing filler metals and the brazing nanopaste.
Authors: Denzel Bridges, Suhong Zhang, Samantha Lang, Minrui Gao, Zhenzhen Yu, Zhili Feng, and Anming Hu
Keywords: Brazing, Nickel Superalloys, Nanojoining, High Entropy Alloys, Nanopaste