About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development
|
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. Moreover, the width of the transition region varies with processing conditions and substrate texture. This study examines the texture transition mechanism and the condition that leads to a larger transition region. Two identical SS316L samples with different printing speeds were printed on a (110) SS316L Single Crystal substrate to ensure uniform initial grain development. The misorientation analysis from the EBSD map shows that the misorientation angle gradually accumulates with the distance from substrate and once it reaches 12~15 degrees, large discontinuous jump in misorientation occurs to form completely new grain. The misorientation angle is related to the growth direction of cellular solidification features and the rate of accumulation is inversely proportional to scan speed. |