| About this Abstract |
| Meeting |
2024 AWS Professional Program
|
| Symposium
|
2024 AWS Professional Program
|
| Presentation Title |
Nickel Aluminum Bronze Wire Arc Additive Microstructure as a Function of Hold Time and Cooling Rate |
| Author(s) |
Alexey Kuprienko, Carolin Fink |
| On-Site Speaker (Planned) |
Alexey Kuprienko |
| Abstract Scope |
Additive manufacturing processes have become an increasingly attractive alternative to conventional casting of large-scale components. Nickel aluminum bronze (NAB) is a commonly used material in naval applications for propeller blades and hub bodies. NAB is a complex alloy system whose room temperature microstructure constituents and phases depend largely on its composition and cooling conditions. In addition to high temperature beta (β) to alpha (α) phase transformation, many small precipitates, collectively referred to as kappa (κ) phases, form upon cooling. While traditional cast NAB microstructures have been well-researched, the complex thermal cycling and rapid cooling associated with additive manufacturing processes necessitate improved understanding of NAB microstructure evolution under these conditions. In this work, the effect of hold time within β phase field and subsequent cooling rate on microstructure of Cu-9Al-4Ni-4Fe alloy were investigated. Cylindrical specimens were extracted from a wire arc additively manufactured multi-bead, multi-layer block deposit. Heating and cooling experiments were performed in a furnace and in a Gleeble thermal-mechanical simulator. Finite element analysis was employed to simulate the wire arc additive process of NAB to aid in selection of test parameters (hold time, cooling rate). Optical microscopy was used to observe general microstructure at low magnifications. Scanning and transmission electron microscopy was used for high magnification microstructure imaging and compositional analysis via energy dispersive X-ray spectroscopy. Electron backscatter diffraction mapping was used for prior β grain reconstruction. Hold time within the β phase field and subsequent cooling rate were shown to have a significant effect on NAB microstructure. Higher cooling rates resulted in a fine eutectoid product in the intergranular regions. The α + κ<sub>iii</sub> lamellae could only be resolved with electron microscopy. Slow cooling resulted in significant coarsening of α grains and intragranular κ<sub>iv</sub> precipitates. |
| Proceedings Inclusion? |
Undecided |