About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Additive Manufacturing of Metals: Applications of Solidification Fundamentals
|
Presentation Title |
Origin of Epitaxy Loss in Laser Powder Bed Fusion |
Author(s) |
Prosenjit Biswas, Ji Ma |
On-Site Speaker (Planned) |
Prosenjit Biswas |
Abstract Scope |
Although the epitaxial growth from the substrate dominates the initial grain development during laser powder bed fusion, epitaxial solidification is lost quickly after a small transition region on the order of <1 to several layer thickness, based on processing conditions and substrate texture. This study examines the texture transition mechanism and the condition that leads to a larger transition region. Two SS316L samples with different printing speeds were printed on an SS316L Single Crystal substrate. The misorientation analysis from the cellular-solidification features and the EBSD map shows that the misorientation accumulates from the meltpool boundary to the center to accommodate for the change in local temperature gradient direction towards the meltpool center. This misorientation continuously accumulates from layer to layer, starting from the substrate, contributing to a large discontinuous jump, once reaches 12°~15°, to form a completely new grain. The rate of accumulation is inversely proportional to scan speed. |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, Solidification, |