"I have a hard time believing that I will go far from material analysis"

William Sjöström, PhD student in mechanical engineering at the Sports Tech Research Centre at Mid Sweden University, spends most of his time in the metal additive manufacturing lab. Dressed in protective clothing and a fresh air mask, he spends his time further developing and streamlining material production.
"Right now, I'm working on developing process parameters for two so-called HTCS steels (high thermal conductivity steel) and reduced elemental tungsten. Tungsten is a bit similar to the ideas realting to ceramics because the melting temperature is over 3400 degrees, however, it is significantly easier to process due to the high conductivity. A majority of the work is to develop a new way of process development that has been made possible with the new equipment from Freemelt.

"Instead of doing about ten builds with about a hundred cubes to be analyzed, I aim to make gradients in the process development. My latest builds give the same data in a sample as 25 samples gave before, through this I can squeeze about 100 experiments into one build instead of about 9 as it was before we had the Freemelt. In addition, we now have the opportunity to scan each layer of the build to get a video from a backwards scattered signal that shows the result even before we start cutting the samples.

In your licentiate thesis from last spring, new methods for creating unique material properties through additive manufacturing were highlighted. Among other things, you introduced the possibility of using ceramic powder in a world record temperature of 1600 degrees. How have you continued to work since then?

"We have bought powder to do more experiments but have not found the time yet, that project has no more funding so it depends on the other projects."

"I would like to work in the direction of being able to replace some metals with new ceramic materials, but it requires a project or that I find the time, right now we only have metal projects underway."

In just over a year, you will be defending your doctoral thesis, what do you hope to be able to show then?

"The thesis will start with what is in the licentiate thesis. The works presented there have now been accepted and published. The work has continued in the direction described in the "future work" section. The idea is to publish the three new materials that are currently being developed as well as the new, more efficient method for materials development. I think it will stitch the work together quite well and shows the enormous development that has taken place since I started working with PBF-EB.

"I have also worked on a few side projects, including developing a process for so-called high entropy alloys and I am investigating whether it is possible to build single crystals by using a single-crystalline seed."

What will you be working on in ten years?

"I find it hard to believe that I will go far from material analysis and material development. These are subjects that there is a lot to do in and that are becoming increasingly relevant in order to achieve a balance between environmental goals and technological development."

"Hopefully, there is the opportunity to continue in AM and perhaps approach professor level. At the same time, I would like to have a little more connection and collaboration with industry, so the dream would be something like a 50/50 distribution between university and industry.

More about Williams' world record

William Sjöström