The Paul Scherrer Institute PSI is the largest research institute for natural and engineering sciences within Switzerland. We perform cutting-edge research in the fields of future technologies, energy and climate, health innovation and fundamentals of nature. By performing fundamental and applied research, we work on sustainable solutions for major challenges facing society, science and economy. PSI is committed to the training of future generations. Therefore, about one quarter of our staff are post-docs, post-graduates or apprentices. Altogether, PSI employs 2200 people. 

For the material aging & structural integrity group at the Laboratory of nuclear materials we are looking for a
Trainee
Corrosion behaviour and surface microstructure (stability) of cavitation-peened surfaces on Alloy 182
Your tasks
Alloy 182 is a Ni-based weld filler metal that is prone to stress corrosion cracking (SCC) during long-term operation of light water reactors. Cavitation peening is a potential mitigation method to prevent SCC initiation by introducing compressive surface residual stresses. However, there may be accelerated relaxation of the compressive residual stress during long-term operation in high-temperature water. Cavitation peening also results in a highly deformed and defective surface affected layer that has a strong driving force for microstructural changes at operating temperature in high-temperature water and, without compressive stresses, an inherently high SCC susceptibility. Within a bigger project, we are evaluating the durability of compressive peening residual surface stresses and related microstructures in long-term operation in high-temperature water and want to demonstrate and quantify the SCC mitigation effect of cavitation peening. In this context you will perform the following supportive experimental investigations:

Your tasks include:
  • Characterization of near-surface microstructure of cavitation-peened and as-machined surfaces before and after thermal ageing and exposure to high-temperature water using optical microscope
  • Cross-sectional hardness profile mapping using micro- and nano-hardness indenters to estimate residual stress relaxations due to thermal and environmental-assisted ageing with time
  • Electrochemical measurements (polarization, EIS) with increasing depth from the surface to investigate electrochemical behaviour of the passive film formed over the defective surface layer under as-peened and aged conditions
Your profile
  • Master student in the field of material science and engineering or equivalent field
  • Solid understanding of material science, corrosion and electrochemistry
  • Basic experience of working in a chemistry laboratory is required. Practical skills in metallographic sample preparation and optical & scanning electron microscopy and some experimental knowledge in electrochemistry would be an asset
  • Proficiency in English is a prerequisite
We offer
Our institution is based on an interdisciplinary, innovative and dynamic collaboration. 

The internship lasts between 3 and 6 months. It takes place between 1 May and 31 October 2024. 

For further information, please contact Dr Annesha Das by phone +41 56 310 26 86 or e-mail annesha.das@psi.ch.

Please submit your application online by 30 March 2024 for the position as a Trainee (index no. 4603-T1).

Paul Scherrer Institut, Human Resources Management, Ladina Goerre, 5232 Villigen PSI, Switzerland