| About this Abstract |
| Meeting |
Superalloys 2024
|
| Symposium
|
Superalloys 2024
|
| Presentation Title |
E-4: Influence of the γ/γ’ Misfit on the Strain-age Cracking Resistance of High-γ’ Ni and CoNi Superalloys for Additive Manufacturing |
| Author(s) |
Stephane A.J. Forsik, Austin Dicus, Gian Colombo, Tao Wang, Mario Epler, Eamonn Connolly, Jiraphant Srisuriyachot, Alexander Lunt, Ning Zhou |
| On-Site Speaker (Planned) |
Stephane A.J. Forsik |
| Abstract Scope |
A series of new printable Ni and CoNi high ã’ superalloys designed for additive manufacturing have been evaluated for strain-age cracking (SAC) resistance. Printability studies and heat treatment experiments were conducted to identify processing windows and characterize the overall resistance to SAC. High-resolution synchrotron X-Ray diffraction experiments were performed to measure the ã and ã’ lattice parameters as a function of the temperature. All the superalloys tested were found to have a positive ã/ã’ misfit at room temperature which decreases as the temperature increases. The misfit of a SAC-prone alloy, 247LC, decreases rapidly and turns negative at about 600 °C, whereas the misfit of superalloys with intermediate resistance to strain-age cracking remains slightly positive. In the three most SAC-resistant superalloys, the misfit remains larger than 0.05 % until at least 883 °C. The results show that a critical aspect for designing SAC-resistant alloys is ensuring that the misfit between ã and ã’ remains positive at all temperatures to generate compressive stresses on grain boundaries. Furthermore, the work also highlights a critical positive misfit value of 0.05% to prevent cracking. |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |