2 dagen geleden - Universiteit Utrecht (UU) - Utrecht
Utrecht University's Faculty of Humanities is looking for a Postdoc position in the Horizon2020 project “Integrity” (0.8 FTE). Are you interested? Then please …
The Eindhoven University of Technology (TU/e) has the following vacancy PhD student "Experimental micromechanics of large scale additive manufacturing" in the Mechanics of Materials group, Department of Mechanical Engineering.
The PhD student position is available in the Mechanics of Materials group, and will be supervised by Dr. Hans van Dommelen, Dr. Johan Hoefnagels and Prof. Marc Geers.
The research activities of the Mechanics of Materials group concentrate on the fundamental understanding of various macroscopic problems in materials processing and forming, 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 needs. The thorough understanding and modelling of 'unit' processes that can be identified in the complex evolving microstructure is thereby a key issue. The group has a unique research infrastructure, both from an experimental and computational perspective. The Multi-Scale Lab allows for quantitative in-situ microscopic measurements during deformation and mechanical characterization and constitutes the main source for all experimental research on various mechanical aspects of materials.
Large-scale additive manufacturing
Additive Manufacturing processes for large scales, such as Direct Metal Deposition (DMD), are based on repeatedly joining material in a locally heated zone and bonding it to a self-supporting substrate, building the desired product layer-by-layer. This manufacturing process creates a specific multi-layered microstructure with highly oriented interfaces and residual stresses originating from high temperature gradients and phase transitions, which will govern the mechanical performance of a material. The goal of this project is to obtain a multi-scale structure-property relationship for products made with large-scale deposition techniques. The main challenge will be to obtain the orientation-dependent mechanical behaviour resulting from the spatially graded microstructure and in particular the effect of interfaces, including grain and phase boundaries, and defects.
Aim of the PhD project
The objective of this PhD project is to experimentally establish a relationship between the microstructure, including defects, resulting from the DMD process and the effective properties of the printed material and the printed product. For this purpose, the microstructures of DMD samples obtained with different processing conditions will be characterized in terms of textures, interface and grain boundary characteristics, voids etc. The mechanical behaviour of the printed microstructures is characterized at the micro-scale and through in-situ mechanical testing, the effects of this microstructure will be determined. The consequence of layer size and grain size through higher order length scale effects and of compositional and microstructural gradients within a layer will be investigated in connection with the microstructure. The presence of internal stress within a multi-layered structure will be characterized at the micro-scale and the mechanical behaviour of printed test samples and of a demonstrator product will be tested at the macro-scale. A phenomenological structure-property relationship will be established based on the morphological and mechanical characterization at different length scales.
Talented, enthusiastic candidates with excellent analytical and communication skills holding a university degree (MSc, with high grades) in Mechanical Engineering, Physics or Materials Science are encouraged to apply. A strong background in mechanics of materials is required. Experience in experimental (micro-)mechanics is of benefit.