On the Role of Boride in the Structural Integrity of a Turbine Disc Superalloy’s Solid State Weld
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Date
2017
Authors
Oluwasegun, K.M.
Olawale, J.O.
Shittu, M.D.
Ige, O.O.
Atanda, P.O.
Ajide, O.O.
Osoba, L.O.
Journal Title
Journal ISSN
Volume Title
Publisher
American Journal of Materials Engineering and Technology
Abstract
This work reports the melting of boride precipitates along the grain boundary of a supposedly solid state
welding of a polycrystalline superalloy, and discusses its attendant effect on the hot ductility behaviour of the alloy.
Nickel-based superalloy used for this study was previously processed by hot extrusion of argon atomized powered
followed by forging. The alloy was solution heat treated at 1120°C, aged at 760°C and subsequently air cooled to
room temperature. Thereafter, it was welded by inertial friction welding (IFW) at a forging pressure of 250 MPa and
finally stressed relieved at 760°C for 8 hours. The microstructures of welded samples were studied by scanning and
scanning transmission electron microscopes. Gleeble hot ductility test was carried out on tensile specimen machined
from the welded sample. The microstructures of the welded alloy shows that boride precipitates liquated along the
grain boundary within the heat affected zone (HAZ) as a result of rapid heating of IFW. The results of hot ductility
test revealed that the melting of boride lowered the hot ductility of the alloy. It was concluded that the boride
precipitates liquated along the grain boundary of the nickel-based superalloy during solid state welding and lowered
its hot ductility.
Description
Staff publications
Keywords
Welding , Hot ductility , Grain boundary , Boride precipitates , Solid state welding , Research Subject Categories::TECHNOLOGY
Citation
Oluwasegun, K.M; Olawale, J.O; Shittu, M.D; Ige, O.O; Atanda, P.O; Ajide, O.O; Osoba, L.O. (2017). On the Role of Boride in the Structural Integrity of a Turbine Disc Superalloy’s Solid State Weld. American Journal of Materials Engineering and Technology, 5(1): 14-23.