Doktorander

Magnus
Jonna
Lisa

Magnus Heldin

Publikationer

Jonna Lind

One challenge for the future is to produce energy-efficient vehicles. This should also be done to a lower price, both when it comes to raw material and production.

Polymeric composites can provide both of these if we compare with metals, which are traditionally used in industry. In addition, polymers have endless possibilities when it comes to solid and internal lubrication. However, more knowledge and better understanding of how polymeric composites behave in tribological contacts is required. That's where my research comes in. If we can understand the basic mechanisms of these materials, we can better develop their use in e.g. automotive industry.

I study high-performance polymeric composites and try to explain its frictional and deformation behavior in tribological contacts. Mechanisms of material transfer and the structure of tribo films are also something I try to understand.

I do this with the help of tribological testing and both surface characteristic and chemical analysis. This includes techniques such as SEM, EDS, XPS and cross-sectional studies.

Part of my project was carried out together with Kongsberg Automotive and funded by the Research Council of Norway.

I have a Master’s degree in Science and Engineering with specialization in Chemical Engineering with a focus on materials at Uppsala University and plan to defend my thesis in the beginning of 2021.

Jonna Holmgren

Education coordinator at Department of Civil and Industrial Engineering, Administration och service

Email:
jonna.holmgren[AT-sign]angstrom.uu.se
Telephone:
+4618-471 5759
Mobile phone:
+46 73 4697220

Lisa Toller-Nordström

PhD student in Engineering Sciences with Specialisation in Tribo Materials

Since 2013 it is known that cobalt powder is carcinogenic upon inhalation. Knowing this, it becomes important to investigate alternatives in processes where cobalt powder is used. One such process is the manufacturing of hardmetals, also known as cemented carbides, where cobalt powder traditionally is used as a binder phase for tungsten carbide.

When alternative binders are used the properties of the hardmetal changes and new phenomena can appear. In my research I try to understand how wear and deformation of hardmetal turning inserts are affected by the change in binder phase.

I use electron microscopy (SEM and TEM) and electron diffraction to study wear and deformation, ranging from macroscopic plastic deformation to small changes in the microstructure.

When cobalt is replaced with an iron rich binder phase it is possible to use the knowledge accumulated in the steel industry. One such project has been to investigate deformation induced martensite. To identify small deformed grains of a different phase in a deformed matrix I have used electron diffraction, including EBSD and TKD in the SEM and SAD and micro-probe in the TEM.

I have a BSc in Chemical Engineering with Engineering Physics and a MSc in Applied Physics from Chalmers University of Technology. I will defend my thesis 6 December 2019.

Elin Larsson

PhD student in Engineering Sciences with Specialization in Tribo Materials

A large part of the energy produced in the world is used to overcome friction between surfaces in contact. Friction is present everywhere where surfaces are moving relative each other. This means that there are large possibilities for energy savings by for instance increased component lifetime and enhanced performance as a result of smarter material choices and system design. One way to reduce the friction losses is to lubricate the surfaces in contact and relative motion. My research is focused on different types of lubricants. The applications have varied but some examples are a lubricating additive in fuel to reduce the fuel consumption in engines as well as greases with and without graphene for electrical contacts. I have also evaluated graphene in polymer composites. In my projects I have collaborated with Triboron International, Axel Christiernsson, ABB and Graphmatech.

By tribological testing in simplified lab tests that mimics the thought application we can widen our knowledge about friction- and lubrication mechanisms. Except from testing, analysis of surfaces after being in contact is an important tool to understand what and which changes on the surfaces, often in utmost surface layers, that influence the friction and lubrication.

I have a Master’s degree at Uppsala University in Science and Engineering with specialization in Chemical Engineering with a focus on materials.

Carl Johan Hassila Karlsson

Additive manufacturing is a manufacturing technology which in recent years has received a lot of attention. Additive manufacturing, a concept incorporating several different manufacturing techniques, allows for the manufacturing of components with complex design features, using both conventional and novel materials. As the industry begin to utilize these new manufacturing techniques there will inevitably be many complex questions regarding the microstructure, mechanical performance and tribological properties of additively manufactured components.

My role as a PhD student at Uppsala University is to study the process step, the resulting microstructure and the mechanical performance of materials produced using the Laser Powder Bed Fusing process. To achieve this, I have access to many analytical means e.g. SEM equipped with EDS/EBSD, TEM as well as synchrotron light sources. Furthermore, I asses additively manufactured materials for their tribological properties which are dictated by the microstructure in the surface of the material. The aim of my work is to be able to control the microstructure locally by the means of process control, and by doing so, improve tribological and mechanical properties.

My work is part of a SSF-project with participants from Uppsala University, Lund University, Malmö University and Luleå Tekniska Högskola. Within the project, which has a strong industrial focus, expertise in material analysis, material development and material modelling can be found as well as access to large scale research facilities.

Anders Holmberg

Last modified: 2023-06-26