PhD position Crack-free high accuracy laser powder bed fusion of tungsten

Laser powder bed fusion of tungsten components for nuclear fusion

A key aspect to enable nuclear fusion as a cost-effective and reliable energy source is how to mitigate the heat load on the reactor wall and ensure its lifetime. A potential solution are liquid metal heat shields, where a liquid metal is captured in a capillary solid skeleton. High purity tungsten will be used as the structural skeleton material in liquid metal divertor components. The concept of additive manufacturing, or 3D printing, offers the geometrical flexibility required for these intrinsically complex components. Specifically, the laser powder bed fusion process offers a high geometrical accuracy for the required internal features. However, several of the outstanding properties that lead to the choice of tungsten as the material for the divertor components, at the same time make this material extremely difficult to process by additive manufacturing. A new laboratory for developing these Liquid Metal Shields for fusion (LiMeS-lab), is being jointly set up by DIFFER and TU/e, and includes a laser additive manufacturing facility specifically tailored for refractory metals has been installed at TU/e.

Vacancy for a PhD-student with a focus on computational modelling

In this project, a laser powder bed fusion additive manufacturing process for the fabrication of tungsten components will be developed based on the fundamental understanding of the underlying mechanisms, which is obtained from process modelling and modelling of the structure-property relation of the printed material, including brittle failure. The goal is to obtain control over the microstructure of selective laser melted tungsten such that crack-free high accuracy tungsten components with excellent mechanical properties can be manufactured. For this purpose, you will:

• Develop a computational model of the print process to obtain the local and global thermomechanical fields and the resulting structure formation.
• Model crack formation during the print process using a stochastic micromechanical approach.
• With the modelling framework, and in close collaboration with the experimental work in a parallel project, optimize the laser powder bed fusion process conditions to obtain high quality tungsten components, with both high geometrical accuracy and microstructural integrity.

Section Mechanics of Materials

You will work in the section of Mechanics of Materials (MoM) at the department of Mechanical Engineering at the Eindhoven University of Technology (TU/e). The research activities of the MoM section concentrate on the fundamental understanding of various macroscopic problems in materials processing, forming and application, which emerge from the physics and the mechanics of the underlying material microstructure. The main challenge is the accurate prediction of mechanical properties of materials with complex microstructures, with a direct focus on industrial and societal needs. The thorough understanding and modelling of processes that can be identified in the complex evolving microstructure is thereby a key issue. The section has a unique research infrastructure, both from an experimental and computational perspective.

• A talented, motivated, enthusiastic candidate with strong analytical skills, initiative, creativity, and flexibility.
• An MSc-degree (with high grades) in Mechanical Engineering, Computational Mechanics, or Applied Mathematics.
• A background and strong interest in mechanics of materials and materials science.
• Experience in multi-scale modelling and micromechanics is of benefit.
• Excellent oral communication and writing skills in English.

A challenging job in a dynamic and ambitious university in an interdisciplinary setting and within an international network, with the possibility to present your work at international conferences.
You will work on a beautiful, green campus within walking distance of the central train station. In addition, we offer you:

• Full-time employment for four years, with an intermediate evaluation (go/no-go) after nine months. You will spend 10% of your employment on teaching tasks.
• You're offered an advanced PhD-level training program in the field of Engineering Mechanics, organized by Dutch Graduate School on Engineering Mechanics (engineeringmechanics.nl).
• Salary and benefits (such as a pension scheme, paid pregnancy and maternity leave, partially paid parental leave) in accordance with the Collective Labour Agreement for Dutch Universities, scale P (min. €2,901 max. €3,707).
• A year-end bonus of 8.3% and annual vacation pay of 8%.
• High-quality training programs and other support to grow into a self-aware, autonomous scientific researcher. At TU/e we challenge you to take charge of your own learning process.
• An excellent technical infrastructure, on-campus children's day care and sports facilities.
• An allowance for commuting, working from home and internet costs.
• A Staff Immigration Team and a tax compensation scheme (the 30% facility) for international candidates.