About this Abstract |
Meeting |
Superalloys 2024
|
Symposium
|
Superalloys 2024
|
Presentation Title |
E-5: Microstructural Evolution and Thermal Stability of Additively Manufactured XH67 Nickel-based Superalloy |
Author(s) |
Nithin Baler, Indu Kollapalli, Subhradeep Chatterjee, Dheepa Srinivasan, Rohit Kumar Yadav |
On-Site Speaker (Planned) |
Rohit Kumar Yadav |
Abstract Scope |
A new high strength nickel-based superalloy, XH67, has been fabricated by the laser powder bed fusion process (LPBF). Novel heat treatments via direct aging, solutionizing and aging, were carried out and compared with the as printed alloy, to study the evolution of phase equilibria and bring out the optimum mechanical properties of high strength and good ductility. A strengthened alloy, XH67 shows a high strength of 1040 MPa with a 25 % ductility, after direct aging (size of 10-30 nm and a volume fraction of 25-30 %). The as-printed structure with a cellular-dentritic morphology was retained during direct aging heat treatment contributing to the strength by Hall-Petch strengthening along with precipitation hardening by γ' precipitates. Discontinuous precipitation along the cell boundaries was a unique microstructural feature that are observed in the present alloy. Annealing twins were seen after solution and aging along with coarsening of the precipitates up to 50 nm. Thermodynamic calculation (Thermo-Calc) was used to validate the observed phase evolution as a function of heat treatment. |
Proceedings Inclusion? |
Definite: At-meeting proceedings |