#additive manufacturing #robots #crystallization kinetics

Analysis of crystallization kinetics in large-scale material extrusion process

Background:

Lightweight design has established itself as an essential part of component design and production in most industries. By applying lightweight design concepts, significant improvements in mechanical properties can be achieved while reducing the weight and cost of components. New manufacturing processes are continuously being developed to implement these concepts.

An outstanding example of this is additive manufacturing, which is considered the industrial revolution of the last decade. Thanks to its versatility, it enables the flexible production of complex component geometries. One of the best-known methods of additive manufacturing is material extrusion (MEX), which is used for small-, medium- and large-scale components. At the microstructural level, processes occur in large-scale 3D printing, especially with semi-crystalline thermoplastics, that can significantly affect the properties of the final product. For example, the onset of crystallization can lead to a reduction in adhesion between two extrudate strands.

The aim of this project work is to carry out further experiments in order to gain a better understanding and to further deepen the findings of a preliminary study. The aim is to describe and investigate these processes in more detail.

Problem definition:

In this project work, the focus is on the analysis of crystallization kinetics in the large-scale MEX process. The main objective is to perform experimental tests on non-isothermal crystallization at different cooling rates using differential scanning calorimetry (DSC). The data obtained will then be used to evaluate the crystallization kinetics and integrated into an evolution equation.

Furthermore, the cooling rate achieved by using additional cooling peripherals will also be investigated. Here, the Flash DSC method is to be applied and a feasibility study carried out in advance.

The knowledge gained is then to be applied to the cooling rates occurring in the process in order to enable a targeted evaluation of the crystallization kinetics for the component.

Scope of work:

Familiarization with theory and literature research (e.g. additive manufacturing, crystallization kinetics),
Sample preparation for DSC and Flash DSC,
Execution and evaluation of experimental tests,
incorporation of the results into an evolution equation and
Investigation of crystallization kinetics on a demonstrator.

What we offer:	What we expect:
Ideal conditions for a theoretical and practice-oriented thesis, The availability of the necessary machines and materials for the creation and testing of the components, The necessary software for analysis and determination of the task and The best possible support during the processing time.	Technical degree, e.g. aerospace engineering, mechanical engineering or a comparable course of study, Experimental skills and enthusiasm for innovative manufacturing processes, Interest in challenging issues, as well as a high degree of initiative and team spirit, and Interest in the field of additive manufacturing and materials science.