| About this Abstract |
| Meeting |
MS&T23: Materials Science & Technology
|
| Symposium
|
Additive Manufacturing of Titanium-based Materials: Processing, Microstructure and Material Properties
|
| Presentation Title |
Process-Microstructure-property Relationships in AM Ti-6Al-4V |
| Author(s) |
Anthony D. Rollett |
| On-Site Speaker (Planned) |
Anthony D. Rollett |
| Abstract Scope |
An overview is given of the widely varying microstructures observed in printed Ti-6Al-4V. Laser Hot Wire (LHW) deposits involve melt pools that are a few millimeters in size. The relatively low cooling rates results in mostly basketweave microstructures. Notable features include narrow “white” bands that contain predominantly colony microstructures from a final peak in temperature close to the transus. Orientation mapping via EBSD combined with viscoplastic crystal plasticity captures the anisotropy in tensile properties. For Laser Powder Bed Fusion (LPBF), systematic variations in power and scan speed, holding all other conditions constant, reveal corresponding variations in microstructure (from basketweave to martensitic) and defect density. 4-point bend fatigue shows the expected inverse correlation of life with pore density. The fatigue-based process window is narrower, however, than expected. Combined simulation of temperature history and experimental characterization of parts with variable local cooling reveal significant variations in microstructure and hardness. |