About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
|
Symposium
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Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development
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Presentation Title |
Microstructure Optimization and Cracks Reduction in Cobalt Based Superalloys Processed by Directed Energy Deposition |
Author(s) |
Thibaut Froeliger, Louise Toualbi, Didier Locq, Edouard Chauvet, Arnaud Ferrandez, Rémy Dendievel |
On-Site Speaker (Planned) |
Thibaut Froeliger |
Abstract Scope |
Additive manufacturing of cobalt-based superalloys leads to a high-textured grain microstructure. Due to thermal stresses induced by this technique, cracks can propagate along the most disoriented grain boundaries where high segregations occur.
This work aims to break the columnar microstructure in order to limit the crack emergence. The investigation focuses on the modification and the optimization of the directed energy deposition parameters with no chemical composition change. Appropriate processing parameters, as well as specific scanning strategies, allow the decrease of the cracks density. Moreover, the emission of ultrasonic waves in the melt pool leads to a columnar / equiaxed microstructure transition affecting the crack density. All those results enable a better understanding of the crack initiation and a better control of the material integrity of γ’ cobalt-based superalloys. |