COPGLOW and XPS investigation of recycled metal powder for selective laser melting

ABSTRACT

The purpose of this paper is to compare, in terms of depth composition profile, a recycled hastelloy X powder and a virgin powder of the same alloy. We compare also the COPGLOW (compacted powder glow discharge analysis) method to the more established XPS (X-ray photoelectron spectroscopy) technique, in terms of similarity in reported elemental contents. A good match between the two methods was obtained on the surface of the powder particles (using an etching depth of 1 nm). Similar oxide layer thickness, of about 0.5–1 nm, was found on both powders by COPGLOW. Oxidation sensitive elements, such as Cr, were found on the surfaces by both XPS and COPGLOW on both powders. Surface content of Si appears to have decreased during use in selective laser melting. Finally, the two methods did not otherwise reveal any unexpected features in the depth profiles.

KEYWORDS:

• Additive manufacturing
• metal powder
• hastelloy X
• depth composition profile
• compacted powder glow discharge analysis
• X-ray photoelectron spectroscopy

Acknowledgements

Dr Arne Bengtsson and Dr Irma Heikkilä at Swerea KIMAB AB are acknowledged for useful comments on evaluating the results. The authors are grateful towards the below named funding source funding sources for the opportunity to carry out this research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Pelle Mellin is employed as a Researcher at Swerea KIMAB AB and focuses on powder characterization and hot isostatic pressing, which in many projects is related to Additive Manufacturing. He holds a PhD in Materials Science from KTH Royal Institute of Technology.

Ruslans Shvab is a Postdoc at Chalmers University of Technology and focuses on characterization and modeling of oxides in powder for PM steel. He holds a PhD in Materials Engineering from the Institute of Materials Research of the Slovak Academy of Sciences, in Slovakia.

Annika Strondl is a group leader at Swerea KIMAB AB. She holds a PhD in Materials Science from Chalmers University of Technology and focuses and Additive Manufacturing of Metals.

Mats Randelius is employed as a Researcher at Swerea KIMAB AB and focuses on GD-OES. He holds a licentiate degree in Materials Science from KTH Royal Institute of Technology.

Håkan Brodin is employed as a materials engineer at Siemens Industrial Turbomachinery AB, and an Assistant professor at Linköping University. He holds a PhD in Materials Technology from Linköping University.

Eduard Hryha is employed as an Assistant professor in Powder metallurgy at Chalmers University of Technology. He holds a PhD in Materials Engineering from the Institute of Materials Research of the Slovak Academy of Sciences, in Slovakia.

Lars Nyborg is employed as a Professor of Surface Technology at Chalmers University of Technology. He holds a PhD from Chalmers University of Technology.

ORCID

Pelle Mellin http://orcid.org/0000-0002-8045-6344

Additional information

Funding

VINNOVA is acknowledged for the financial support of the research work (Project 2014-00795 and 2016-01990).