All available topics
The CD Laboratory DEPICT-Al at the Chair of Nonferrous Metallurgy, Montanuniversität Leoben, studies how the microstructural constituents of recycling-relevant aluminium alloys interact with plastic deformation, so that formability, damage tolerance and corrosion resistance are retained as the scrap content rises.
Open thesis topics
The following open topics are designed as master theses. Parts of them can be offered as a bachelor thesis; the scope is agreed with the supervisors. Topics beyond this list are possible on request. Ongoing theses are marked as assigned.
A reference library for Fe-rich phases: phase identification in recycled aluminium by EBSD and EDS
Telling apart phases that look almost identical in chemistry, by their diffraction patterns.
Details →Strain fields around needle-shaped precipitates: strain mapping by 4D-STEM in 6xxx alloys
Making lattice strain visible at the nanometre scale, where dislocations meet precipitates.
Details →Grain boundaries as nucleation sites: effect of grain size on MgZn2 precipitation in 7050
How much grain boundary can a thick plate afford during quenching?
Details →Where does a sheet fail first? Strain localisation in tensile testing by digital image correlation
From an average over the gauge length to a full strain map.
Details →Which element costs formability? Individual alloying elements in 6016 body sheet
One alloy, one process, one element: cleanly separated causes of forming behaviour.
Details →After the paint oven: age hardening and forming behaviour of 6xxx sheet after paint baking and in the T6 condition
Does the ranking of the alloys hold when the matrix becomes harder?
Details →Aluminium under extreme load: high-Mg 5xxx alloys under ballistic loading
High strain hardening meets the highest strain rates.
Details →Corrosion and recycling: corrosion behaviour of 7050 plate through the thickness
Which particles and grain boundaries trigger the attack, and where in the plate?
Details →A reference library for Fe-rich phases: phase identification in recycled aluminium by EBSD and EDS
Research domain B of the laboratory advances the characterisation methods and asks how the interaction of deformation and precipitation in recycling-relevant aluminium alloys can be made visible and measurable from the nanometre to the millimetre scale.
What it is about
Every percent of scrap brings more iron, manganese, silicon and copper into an aluminium alloy. These elements form intermetallic phases such as Al13Fe4, Al6(Fe,Mn), α-Al(Fe,Mn)Si, β-Al5FeSi or Al7Cu2Fe, and which of them forms decides formability and fracture behaviour. The difficulty is that several of these phases have almost the same chemical composition, so EDS alone cannot separate them, and their large, low-symmetry unit cells are beyond what commercial EBSD software handles well.
The laboratory has therefore developed its own licence-free EBSD platform, which simulates Kikuchi patterns directly from the crystal structure and indexes them on the graphics card. In this thesis you build the foundation that turns the method into a routine tool: a verified reference library of the Fe-, Mn-, Si- and Cu-bearing phases. This makes phase identification a routine step, in the laboratory as well as in industrial application.
What you will do
- Collect crystal structure data (CIF) from the literature and databases and check them critically
- Simulate dynamical master patterns and assess how well similar phases can be distinguished
- Validate on reference alloys with known phases in the scanning electron microscope (EBSD and EDS)
- Define identification criteria that combine the diffraction pattern with the chemical signature
- Apply the library to alloys from research domains A and C
Methods
What you bring
Suited to students of materials science, metallurgy, physics or chemistry with an interest in crystallography and in combining experiment and simulation. Experience in Python is helpful but not required.
As a bachelor thesis: Building and validating part of the library, for example the phases of the Al-Fe-Si system.
- Supervision
- Dr. mont. Sebastian Samberger
- Start
- by arrangement
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Contact
- Dr. mont. Sebastian Samberger
sebastian.samberger@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at
Strain fields around needle-shaped precipitates: strain mapping by 4D-STEM in 6xxx alloys
Research domain B of the laboratory advances the characterisation methods and asks how the interaction of deformation and precipitation in recycling-relevant aluminium alloys can be made visible and measurable from the nanometre to the millimetre scale.
What it is about
The strength of age-hardenable Al-Mg-Si alloys comes from nanometre-sized, needle-shaped precipitates. They are coherent with the matrix and distort the surrounding crystal lattice, and these strain fields determine how dislocations interact with the precipitates. They can be measured by 4D-STEM: a focused electron beam scans the specimen and records a complete diffraction pattern at every point. The position of the diffraction discs gives the local lattice strain with a spatial resolution in the nanometre range.
A first dataset of an aged 6xxx extrusion is available from the cooperation with the Erich Schmid Institute. In this thesis you develop a validated evaluation workflow from it and then apply it to new 6xxx plate material. The workflow is the basis for later in-situ deformation experiments on the laboratory's own microscope.
What you will do
- Build the evaluation workflow for strain maps: calibration, disc detection, reference region, strain components and error estimate
- Validate it on the existing dataset of the 6xxx extrusion
- Prepare TEM thin foils from new 6xxx plate material
- Carry out measurements on the transmission electron microscope (4D-STEM, SPED) together with the team
- Compare the strain fields between material conditions and relate them to the strengthening mechanisms
Methods
What you bring
Suited to students of materials science, physics or metallurgy with an interest in electron microscopy and quantitative data analysis. Basic knowledge of Python or a comparable language is an advantage.
As a bachelor thesis: Building and validating the evaluation workflow on the existing dataset, without own measurements.
- Supervision
- Dr. mont. Thomas Kremmer, DI Christoph Brandner
- Start
- by arrangement
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Cooperation
- in cooperation with the Erich Schmid Institute of the Austrian Academy of Sciences
- Contact
- Dr. mont. Thomas Kremmer
thomas.kremmer@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at
Grain boundaries as nucleation sites: effect of grain size on MgZn2 precipitation in 7050
Research domain C of the laboratory studies thick plate of the aerospace alloy 7050 and asks how thermomechanical processing and recycling-related tramp elements set the microstructure and thereby fracture toughness and corrosion resistance.
What it is about
After solution treatment, thick 7050 plate cools more slowly in the core than at the surface. During this slower cooling, η-MgZn2 precipitates preferentially at the grain boundaries. This consumes solute that is later missing for age hardening, creates precipitate-free zones and affects fracture toughness and stress corrosion cracking. Since grain boundaries are the nucleation sites, the obvious question is how strongly the grain size controls the quench sensitivity. It has not yet been answered quantitatively.
In this thesis you set different grain sizes in 7050 on purpose and measure how cooling-induced precipitation changes with the grain-boundary area. The aim is a quantitative description of the grain-boundary contribution to nucleation that can be incorporated into mean-field precipitation models. The results connect directly to the through-thickness fracture toughness measurements of the laboratory.
What you will do
- Set the grain size through the degree of cold rolling and recrystallisation during solution treatment
- Measure precipitation during defined cooling rates by differential scanning calorimetry (DSC)
- Characterise grain-boundary precipitates and precipitate-free zones by SEM, optionally by TEM with research domain B
- Evaluate the quench sensitivity as a function of grain size and cooling rate
- Optional: simple modelling of grain-boundary precipitation, or extension to 2xxx alloys (S phase) or a 5/7 crossover alloy (T phase)
Methods
What you bring
Suited to students of metallurgy or materials science with an interest in phase transformations, thermal analysis and microscopy.
As a bachelor thesis: A DSC series at several cooling rates for two grain sizes, complemented by SEM characterisation.
- Supervision
- Dr. Robert Kahlenberg
- Start
- by arrangement
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Contact
- Dr. Robert Kahlenberg
robert.kahlenberg@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at
Where does a sheet fail first? Strain localisation in tensile testing by digital image correlation
Research domain A of the laboratory studies sheet made from recycling-relevant 5xxx and 6xxx alloys and asks how solutes, primary phases, dispersoids and precipitates interact with deformation, and how ductility and formability can be retained despite increasing contents of tramp elements.
What it is about
A tensile curve averages over the whole gauge length. What happens locally stays hidden: the onset of necking, shear bands, or the travelling Portevin-Le Chatelier bands that make deformation in Al-Mg alloys jerky. Digital image correlation (DIC) tracks a random speckle pattern on the specimen surface from image to image and computes a complete strain field from it.
A camera system is available at the chair. In this thesis you find out whether it is sufficient for the questions of the laboratory and establish the method, from speckle preparation, lighting and calibration to synchronisation with the testing machine and the extensometer. You then make strain localisation in aluminium sheet visible. The data also serve as a reference for crystal-plasticity simulations, and your results help decide whether an upgrade of the equipment is needed.
What you will do
- Assess the existing camera system: spatial and strain resolution, alignment, triggering, lighting, compatibility with extensometers
- Develop a reproducible speckle preparation
- Carry out tensile tests on aluminium sheet, including strain-rate jump tests, and evaluate the local strain fields
- Visualise Portevin-Le Chatelier bands and localisation before fracture
- Draft a concept for extending the method to bending and cupping tests
Methods
What you bring
Suited to students of materials science, metallurgy, mechanical engineering or physics with an interest in mechanical testing and measurement. Experience with image processing or programming is an advantage.
As a bachelor thesis: Commissioning and validating the system on simple tensile tests.
- Supervision
- Dr. mont. Philip Aster
- Start
- from the first quarter of 2027
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Contact
- Dr. mont. Philip Aster
philip.aster@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at
Which element costs formability? Individual alloying elements in 6016 body sheet
Research domain A of the laboratory studies sheet made from recycling-relevant 5xxx and 6xxx alloys and asks how solutes, primary phases, dispersoids and precipitates interact with deformation, and how ductility and formability can be retained despite increasing contents of tramp elements.
What it is about
Car body sheet made from alloy 6016 has to be hemmed and bent around tight radii. With an increasing scrap share its composition changes, and even small changes that hardly show in the tensile test can cause a sheet to fail this qualification. Which element is responsible, and through which microstructural constituent it acts, is often unclear, because in practice composition and process change at the same time.
This thesis separates the causes: the processing route is kept fixed and industrially oriented, and only one alloying element is varied at a time. You follow the entire route on laboratory scale, from alloy selection supported by thermodynamic calculations through casting and rolling to forming tests, and link the result to primary phases, texture and ageing condition.
What you will do
- Alloy selection supported by thermodynamic calculations
- Laboratory-scale production: casting, homogenisation, hot and cold rolling, solution treatment
- Tensile, bending and hardness testing, optionally cupping tests, in the T4 condition and after the paint-bake cycle
- Microstructural characterisation by SEM, EDS and EBSD: size, spacing and arrangement of primary phases, texture
- Correlation of composition, microstructure and formability
Methods
What you bring
Suited to students of metallurgy or materials science who enjoy practical laboratory work along the entire process chain.
As a bachelor thesis: Study of a single element with a reduced test matrix.
- Supervision
- Dr. Irmgard Weißensteiner, DI Stefan Pfundner
- Start
- by arrangement
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Contact
- DI Stefan Pfundner
stefan.pfundner@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at
After the paint oven: age hardening and forming behaviour of 6xxx sheet after paint baking and in the T6 condition
Research domain A of the laboratory studies sheet made from recycling-relevant 5xxx and 6xxx alloys and asks how solutes, primary phases, dispersoids and precipitates interact with deformation, and how ductility and formability can be retained despite increasing contents of tramp elements.
What it is about
Car body sheet made from 6xxx alloys is formed in the soft, naturally aged T4 condition and reaches its final strength only in the paint oven, when fine precipitates form. This changes the hardening of the matrix, and with it the question of how well the sheet tolerates its primary phases. Whether an alloy that performs well in T4 also does so after paint baking and in the T6 condition is not self-evident.
In this thesis you study exactly this transition on the model alloys of the laboratory. You follow the hardness evolution, test strength, strain hardening and bendability, and infer the precipitation state from the mechanical data and complementary measurements.
What you will do
- Heat treatments: T4 condition, simulated paint-bake cycle, artificial ageing to T6
- Hardness evolution over ageing time
- Tensile and bend tests with evaluation of strain hardening (Kocks-Mecking analysis)
- Complementary characterisation of the precipitation state, for example by DSC
- Comparison of the alloy ranking in T4, after paint baking and in T6
Methods
What you bring
Suited to students of metallurgy or materials science with an interest in precipitation hardening and mechanical testing.
As a bachelor thesis: Hardness evolution and tensile tests on a selection of the alloys.
- Supervision
- Dr. Irmgard Weißensteiner, DI Stefan Pfundner
- Start
- by arrangement
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Contact
- DI Stefan Pfundner
stefan.pfundner@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at
Aluminium under extreme load: high-Mg 5xxx alloys under ballistic loading
Research domain A of the laboratory studies sheet made from recycling-relevant 5xxx and 6xxx alloys and asks how solutes, primary phases, dispersoids and precipitates interact with deformation, and how ductility and formability can be retained despite increasing contents of tramp elements.
What it is about
Aluminium alloys with about 10 wt.% magnesium show exceptionally strong strain hardening. The laboratory has shown that such sheet reaches bend angles well above 120° after annealing while retaining high strength. Established Al-Mg alloys are already used in shipbuilding and protective applications. How the high-Mg variants behave under ballistic loading, at extreme strain rates, with adiabatic heating and the risk of shear banding, is an open question.
In this thesis you produce the alloys, process them in a controlled way and accompany ballistic tests at an external test facility. The focus is on what happens in the microstructure around the impact zone and how this relates to the processing route and the quasi-static properties.
What you will do
- Literature survey on high-Mg 5xxx alloys under dynamic loading
- Production by melting and casting, thermomechanical processing by homogenisation, hot and cold rolling and heat treatment
- Quasi-static testing: hardness and tensile tests
- Definition of the test matrix, preparation and accompaniment of the ballistic tests
- Characterisation of the impact zone by SEM and EBSD: local deformation, shear bands and damage
Methods
What you bring
Suited to students of metallurgy, materials science, mechanical engineering or related fields with an interest in materials testing and microstructural characterisation. Prior experience with SEM or EBSD is an advantage but not required.
As a bachelor thesis: Production and quasi-static characterisation of one alloy, with microstructural analysis of selected impact specimens.
This topic is in preparation. Material of suitable gauge, specimen geometry, safety concept and access to the external test facility are currently being clarified. Interested students are welcome to get in touch already.
- Supervision
- Dr. mont. Philip Aster
- Start
- in preparation
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Contact
- Dr. mont. Philip Aster
philip.aster@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at
Corrosion and recycling: corrosion behaviour of 7050 plate through the thickness
Research domain C of the laboratory studies thick plate of the aerospace alloy 7050 and asks how thermomechanical processing and recycling-related tramp elements set the microstructure and thereby fracture toughness and corrosion resistance.
What it is about
High-strength 7xxx alloys are susceptible to localised corrosion and stress corrosion cracking. The initiation sites are frequently intermetallic particles: copper- and iron-bearing phases such as Al7Cu2Fe act cathodically with respect to the matrix, whereas the S phase Al2CuMg initially behaves anodically and can transform into copper-rich remnants by selective dissolution. When the iron and silicon contents rise with the recycled share, this particle population changes, and in thick plate the microstructure changes through the thickness as well.
This master thesis studies three plate variants of alloy 7050 at three positions through the thickness and links the corrosion behaviour to the phase survey and the grain-boundary network that the laboratory has already recorded in these plates. It also establishes the test set-up for stress corrosion cracking on which the future doctoral project of the research domain builds.
Work programme
- Immersion tests, potentiodynamic polarisation and electrochemical impedance spectroscopy on three plate variants at three positions
- Intergranular corrosion testing as reference
- SEM and EDS of the attack sites and correlation with the phase population and the grain-boundary network from EBSD data
- Set-up of a stress corrosion cracking test: constant-deflection four-point bending with alternate immersion
Methods
- Student
- Sarah Daniel, BSc
- Supervision
- Dr. mont. Sebastian Samberger, Dr. Irmgard Weißensteiner
- Start
- 2027
- Location
- Chair of Nonferrous Metallurgy, Montanuniversität Leoben
- Contact
- Dr. mont. Sebastian Samberger
sebastian.samberger@unileoben.ac.at
Dr. Irmgard Weißensteiner
irmgard.weissensteiner@unileoben.ac.at