PhD position: Measurement concept for fatigue condition assessment

Remanufacturing of steel products, in particular bearings, is a promising method to make more efficient use of materials and resources and hence to reduce the emissions associated with the production of new steel for these applications. The main challenge in increasing the market share of remanufactured steel products is the ability to measure the accumulated sub-surface fatigue damage during prior use of the material. Currently, there is no non-destructive and non-intrusive method to measure the characteristics of the microstructure of the material that can reveal the accumulated fatigue damage. This research project aims at developing the measurement technology that will make this possible. Initially, the focus will be on medium sized bearings, such as for example used in railway applications, while a generalisation to for example structural steel is foreseen in the last phase of the research.

From a theoretical point of view, it is known that martensitic phases in hardened steel, as used in bearings, tend to degrade before the formation of microcracks, marking the onset of (rolling contact) fatigue damage. It is also established that both electromagnetic and ultrasonic measurement methods are sensitive to microstructural changes. However, a quantitative relation between the phase transformations and early microcracks, on the one hand, and one or more measurable features, on the other hand is not yet available. Moreover, the sensitivity and accuracy of these measurement methods for detecting such early-stage damage remain insufficiently understood. Microstructure-level models will be developed to investigate and quantify the interaction between microstructure properties and measurable features. This modelling will be supported by targeted experimental work, aiming to establish a robust method for assessing accumulated fatigue damage in a remanufactured bearing and, more generally, in remanufactured steel components.

• You have obtained MSc. Degree in Mechanical/Material Engineering or a related discipline with excellent results and special interest in Non-Destructive Testing (NDT) methods. Prior knowledge in experimental and computational methods and material science is strongly recommended. Ideally, you have experience with electro-magnetic and/or ultrasonics based Non-Destructive Testing methods.
• You are interested in working in a multidisciplinary team, consisting of academic fellows and experts, as well as industrial experts. You take a pro-active role in the strong collaboration that is expected with SKF, the main industrial partner in the project.
• You have a strong capacity for independent problem-solving, creative thinking, responsible attitude and are highly motivated to make your project a success, together with all academic and industrial partners.
• Your ambition is to develop yourself and give a meaningful contribution to the project and all its stakeholders.

We encourage candidates with strong communication skills who like to present their work at conferences and (project) meetings. Proficiency in English is required, both spoken and written. You need to provide IELTS test results (minimum score 6.5), TOEFL-iBT (minimum score 90).

Please submit your application before July 28th, 2025, using the "Apply now" button, and include the following:

• Curriculum vitae
• Letter of motivation
• Transcripts from your BSc and MSc courses
• IELTS or TOEFL score
• Contact information of 2 references

First (online) interviews will be held on mid to end of August 2025.
Screening is part of the selection procedure.

For more information, you can contact dr.ir. Richard Loendersloot email: r.loendersloot@utwente.nl.