About this Abstract |
Meeting |
Materials Science & Technology 2020
|
Symposium
|
Materials Informatics for Images and Multi-dimensional Datasets
|
Presentation Title |
Keyhole Porosity Threshold in Laser Melting Revealed by High-Speed X-ray Imaging |
Author(s) |
Runbo Jiang, Benjamin Gould, Andy Ramlatchan, Joseph Aroh, Anthony Rollett |
On-Site Speaker (Planned) |
Runbo Jiang |
Abstract Scope |
It’s generally accepted that operation outside the conduction regime results in the formation of subsurface trapped gas pores (i.e. keyhole pores). However, the transition between conduction and keyhole mode inducing subsurface porosity is relatively large and not well explored. In-situ high-speed x-ray imaging has proven useful in investigating the keyhole behavior of laser powder bed fusion. The undulation of the area and the variance of front wall angle of the vapor cavity were measured in each time frame in x-ray images. It was found that the boundary in between is not discrete. A threshold of keyhole pore formation in Al6061 and IN718 was determined. Operation under keyhole condition can lead to faster print time. Therefore, if the keyhole porosity threshold facilitates the use of this mode without the formation of porosity, build rate can be significantly improved. Alternative methods are being used to expand this transition regime. |