Master thesis: Increased utilization of gas atomized powders in AM

We want to be more! The research institute Swerim conducts needs-based industrial research and development concerning metals and their route from raw material to finished product. Swerim has 200 co-workers in two locations in Sweden - Luleå and Stockholm. Our vision is a fossil-free and circular industry.

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Figure 1. Size of gas atomised powder manufactured at Swerim (left). Contour melting in PBF-EB (right).
 

Gas atomized powders are created by dispersing molten alloy using high-speed gas. Ideally, the particle sizes produced would match the intended application without needing further processing. For example, additive manufacturing (AM) typically requires particle sizes of 15-45 µm or 45-150 µm, depending on the capabilities and limits of Powder Bed Fusion by Laser Beam (PBF-LB) or Electron Beam (PBF-EB) technologies. However, the gas atomization process inherently produces a wider range of particle sizes, necessitating separation into specific fractions. This separation process increases costs, posing a significant barrier to widespread adoption.

To overcome this challenge, optimizing particle size distributions (PSDs) and increase the yield of the gas atomization is essential. One way is to further optimize the gas atomization process, but this project will focus on the usage of the powder. Smaller particles can fill gaps between larger ones, but they may decrease flowability, leading to irregularities in the powder bed. These irregularities can negatively affect the relative density, mechanical properties, and accuracy of the printed part. Conversely, larger particles improve flowability but may reduce density and mechanical properties [1].

Project description
The project will look into the economic and environmental benefits of increased utilization of gas atomized powder as a part of a literature review and data gathered during the project. Different fractions of powder will be created using the powder and equipment available at Swerim. These fractions will be characterized in Swerim’s powder lab in terms of flowability, spreadability, packing density and particle size, and morphology. Relevant fractions will then be selected for print trials in Swerim’s AM-machines: SLM 280 2.0 (PBF-LB) and Arcam S12-AX (PBF-EB). Depending on the success of the trials, the parts are analyzed in terms of porosity, microstructure and surface roughness. Additionally, the influence of PSD and AM-technique is investigated.   
 
The project will be primarily conducted by the student, with support from colleagues at Swerim. The student will have the autonomy to shape the work and determine the types of analyses to be performed.

Required qualifications
Student in material science, chemistry engineering, or similar fields. Any experience or prior knowledge about metal powder, AM, laboratory work or working in an industry and/or research environment will be considered as an advantage.
 
Further information
Swerim rewards the student with 50 000 SEK for an approved master thesis (30hp).  
 
The work will be initiated at the beginning of 2025.
 
Contact
For further information about project, please contact: Emil Strandh, emil.strandh@swerim.se

Application
Apply by using the application function below. Please note that we fill the thesis as soon as we find a suitable applicant, which means we can fill the position before the deadline. You will receive a confirmation that Swerim has received your application. The work should be initiated during the beginning of 2025.


 
[1] Ludwig, I.; Kluge, M. Investigation of an Increased Particle Size Distribution of Ti-6Al-4V Powders Used for Laser-Based Powder Bed Fusion of Metals. Materials 2024, 17, 2942. https://doi.org/10.3390/ma17122942