Selective laser melting (SLM) is a powder bed based additive manufacturing process in which a layer of powder is laid over the surface of a substrate and a laser with sufficient energy is employed to selectively melt particles to build a part layer by layer. During the SLM process, dark smoke was observed coming off of the powder bed surface where the laser was interacting with powder. This phenomenon resulted from heat-affected powder that was visibly different than the base powder. Since the concentration of the heat-affected powder differs throughout the build chamber as a result of the recirculating argon gas flow, powder samples from different regions were collected for analysis. The heat-affected powder samples were analyzed by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD) in order to distinguish differences between the heat-affected powder and the base 304L stainless steel powder. The influences of the heat-affected powder on the microstructure and tensile properties of parts built in different areas of the build chamber are also investigated.

Meeting Name

27th Annual International Solid Freeform Fabrication Symposium -- An Additive Manufacturing Conference (2016: Aug. 8-10, Austin, TX)


Mechanical and Aerospace Engineering

Second Department

Materials Science and Engineering

Research Center/Lab(s)

Intelligent Systems Center


This work has been funded by Honeywell Federal Manufacturing & Technologies under Contract No. DE-NA0002839 with the U.S. Department of Energy.

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type




Publication Date

10 Aug 2016