Student Works

Type: Scientific Project

Group: Biomaterials

Research Objective

In recent years, additive manufacturing has emerged as a key technology for the production of plastic components. In particular, the polymer polylactide (PLA) is widely used in the fused-layer modeling (FLM) process due to its good processability, its bio-based origin, and its versatile applications. The mechanical and thermal properties of PLA components are significantly influenced by their crystallinity, which in turn depends on the selected process parameters during the printing process.

X-ray diffraction (XRD) is an established and powerful analytical method for characterizing the crystalline fraction in additively manufactured PLA samples. By analyzing the diffraction patterns, conclusions can be drawn about the crystal structure and the degree of crystallinity of the material.

The objective of this project is the additive manufacturing of PLA test specimens under defined process conditions, followed by the subsequent investigation and evaluation of their crystallinity using X-ray diffraction. The aim is to analyze the relationship between the manufacturing parameters and the resulting degree of crystallinity.

The objective of this project is the additive manufacturing of PLA test specimens under defined process conditions, followed by the analysis and evaluation of their crystallinity using X-ray diffraction. The aim is to analyze the relationship between the manufacturing parameters and the resulting degree of crystallinity.

• The project specifically includes:

• the production of PLA test specimens using additive manufacturing (FLM process) 

• the selection and documentation of suitable printing parameters 

• the performance of XRD measurements to determine the crystal structure 

• the evaluation and assessment of the diffraction data with regard to the degree of crystallinity 

• the analysis of the influence of manufacturing parameters on crystallinity 

• the evaluation of the significance and limitations of the applied investigative method 

The goal is to gain a better understanding of the relationship between additive manufacturing and crystallinity development in PLA components and to evaluate the suitability of XRD analysis for material characterization.

Contact Person: Steffen Sowka

Type:  Master's thesis

Groupe: Lightweight Structures

Aluminum–silicon cast alloys are widely used in lightweight structures for automotive and aerospace applications due to their high strength-to-weight ratio and castability. However, their long-term performance is strongly influenced by casting defects (such as pores and oxides), microstructural heterogeneities, and environmental conditions (humidity, temperature). To ensure reliable service life prediction, these factors must be systematically investigated under realistic loading scenarios.

This thesis project focuses on the experimental investigation of fatigue damage mechanisms in cast Al-Si alloys under high-cycle (HCF) and very-high-cycle (VHCF) fatigue loading. The work will include:

• Preparation and testing of alloy specimens under defined environmental and loading conditions.
• Use of in-situ monitoring techniques (hysteresis analysis, thermography, potential drop methods).
• Computed tomography (CT) for 3D defect and crack characterization.
• Correlation of experimental results with microstructural features and defect populations.

The results will provide valuable input for mechanism-based life prediction models and contribute to the development of more reliable lightweight structures.

Contact Person: Dr. Sudip Kundu, PhD

Typ: Initiativbewerbungen für Projekt‐/ Bachelor‐/ Masterarbeiten

Gruppe:  Process Control

Zur Herstellung von Stahlkomponenten für die Automobil‐, Luftfahrt‐, Energie‐ und Offshore‐Industrie werden zahlreiche trennenden, umformende und fügende Fertigungsverfahren eingesetzt, die die Lebensdauer der Komponenten unter Betriebsbeanspruchungen signifikant beeinflussen. In den studentischen Arbeiten der Gruppe Stähle werden der Einfluss der Fertigungsverfahren unter Einsatz kombinierter In‐Prozess‐Messtechnik untersucht, die zugrundeliegenden mikrostrukturellen Eigenschaften charakterisiert und mit dem mechanismenbasierten Ermüdungsverhalten unter realitätsnahen Beanspruchungen korreliert.

Die Arbeiten umfassen grundsätzlich die Durchführung experimenteller Untersuchungen an elektromechanischen, servohydraulischen und elektromagnetischen Prüfmaschinen und die Anwendung mechanischer, thermometrischer, elektrischer, magnetischer, optischer und elektrochemische Messsysteme. Für die mikrostrukturellen und analytischen Untersuchungen werden Licht‐ und Elektronenmikroskopie sowie Röntgendiffraktometrie eingesetzt.

Kontaktperson: M.Sc. Lars Andree Lingnau