| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Additive Manufacturing: Qualification and Certification
|
| Presentation Title |
Physics-based Qualification for Laser Powder Bed Fusion AM |
| Author(s) |
Anthony D. Rollett |
| On-Site Speaker (Planned) |
Anthony D. Rollett |
| Abstract Scope |
A multi-institution team is investigating a physics-based approach to qualification of laser powder bed fusion (LPBF) machines. By printing Ti-6Al-4V under a variety of conditions of power, speed and hatch spacing, the dependence of porosity and fatigue strength is quantified. The same model of LPBF machine is used at different institutions, along with other makes. Process windows are defined by keyhole porosity on the high power side and lack-of-fusion porosity on the high speed side. 4-point bend fatigue provides an efficient method for quantifying variations in fatigue. Amongst many other factors, controlling raster length is crucial for avoiding defects. A related effort in wire-feed robotic welding of scandium-modified Al alloys also leads to a process window in P-V space bounded by a limit on porosity that provides an analogous basis for qualification. Contributions from the many team members and support from the NASA ULI Program are gratefully acknowledged. |