Description
The development of new titanium alloys tailored for wire-based directed energy deposition (waDED) processes is to enable the wider uptake of this novel processing route by the aerospace and energy industries. While there has been significant focus on developing high-strength Ti-alloys for waDED, the development of new high-temperature titanium alloys has been limited so far despite the high temperatures experienced by parts in aerospace and energy. Further, previous studies have demonstrated that waDED techniques often lead to significant heterogeneity and anisotropy in the mechanical properties of existing high-temperature titanium alloys, such as Ti-6Al-2Sn-4Zr-2Mo.In the present work, a novel high-temperature Ti alloy has been developed, aiming to improve the high-temperature performance via exploiting phase transformations and precipitation to achieve fine and homogeneous microstructures during AM processing. Our new alloy design features combined additions of Si, Cu, Nb, and Y. We study its microstructural evolution during the simulated waDED solidification route and after various heat treatments that replicate cyclic reheating following waDED. Our new alloy shows significant potential for high-deposition-rate waDED processes and exhibits fine and equiaxed β grains after heat treatment. In addition, the presence of Y inhibits β grain growth and the microstructure transforms from a fine lath-like colony α-phase into a coarse lamellar pearlitic microstructure during the heat treatment. High-resolution atom probe microscopy reveals very fine (15–20 nm) core-shell Ti2Cu precipitates with Y in their cores. These precipitates contribute to a significant improvement in mechanical performance, despite observed microstructure coarsening during heat treatment.
| Period | 7 Jul 2025 → 11 Jul 2025 |
|---|---|
| Event title | The 9th International Conference on Solid-Solid Phase Transformations in Inorganic Materials |
| Event type | Conference |
| Location | Delft, NetherlandsShow on map |
Research Field
- Wire-Based Additive Manufacturing