NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Surface Feature Characteristics of Laser Powder Bed Fusion of Nickel Super Alloy 625 Bulk Regions
Published
Author(s)
Jason Fox, Romaine Isaacs, Aarush Sood, Paul Brackman, Brigid Mullany, Edward Morse, Angela Allen, Edson Santos, Christopher Evans
Abstract
Coherence scanning interferometry (CSI) and scanning electron microscopy (SEM) surface inspection of additively manufactured nickel super alloy 625 reveal features over a broad range of length scales beyond those typically reported. High resolution measurements show micrometer-scale dendritic periodicity over 10's-of-micrometers length scales, often with a circular geometry. Larger-than-anticipated solidified melt tracks are observed near laser path turnarounds, presumably resulting from fusion of adjacent melt pools and cooling rate differences. The dendritic texture variability directly indicates microstructure variation, and further microstructure variation is likely correlated with the melt pool variation, as well. This raises concerns about final material properties and homogeneity.
Fox, J.
, Isaacs, R.
, Sood, A.
, Brackman, P.
, Mullany, B.
, Morse, E.
, Allen, A.
, Santos, E.
and Evans, C.
(2022),
Surface Feature Characteristics of Laser Powder Bed Fusion of Nickel Super Alloy 625 Bulk Regions, Procedia CIRP, Lyon, FR, [online], https://doi.org/10.1016/j.procir.2022.03.083, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933943
(Accessed October 9, 2025)