About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Titanium Technology
|
| Presentation Title |
Grain Boundary α Formation in Ti-6Al-4V Fabricated via Laser-Based Powder Bed Fusion with Preheated Substrates |
| Author(s) |
Tiantian Wang, Shenglu Lu, Milan Brandt, Ma Qian |
| On-Site Speaker (Planned) |
Tiantian Wang |
| Abstract Scope |
Grain boundary α (GB-α) in titanium alloys degrades mechanical performance and remains difficult to suppress due to incomplete understanding of its formation mechanisms. This study examines the role of crystallographic orientation between adjacent prior-β grains and transformation pathways in preferential formation of GB-α in laser-based powder bed fusion (PBF-LB) Ti-6Al-4V built on preheated substrates. A crystallographic parameter, θ2-BOR, which quantifies the deviation between two adjacent prior-β grains from a reference arrangement, is employed to decode preferential formation of GB-α. A critical θ2-BOR threshold is identified, beyond which GB-α formation is inhibited. At 500 °C substrate temperature, continuous GB-α selectively forms when cooling from the β phase field at specific prior-β GBs, maintaining a Burgers orientation relationship with both prior-β grains. Additional heat treatments above and below the β-transus clarify the influence of transformation pathways. These findings provide guidance for controlling GB-α through tailored thermal processing and texture design in additive manufacturing. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Titanium, Phase Transformations |