Metallurgy Group of the Department of Management and Engineering – School of Engineering

Department

Department of Management and Engineering – School of Engineering

Main research activities/topics/projects

The main objective of the research is the study of innovative wrought aluminium alloys to be used for producing rheocast components with complex geometry, such as thin wall thicknesses and hollow. The research will be in the field of Metallurgy. The research activity will be divided into two main tasks.
Task 1: Thermodynamic analysis and investigation of the physical/rheological properties of a new wrought aluminium alloy for rheocasting applications.
The first activity involves the thermodynamic analysis and the study of the physical and rheological characteristics of a new secondary aluminium alloy generally applied during plastic deformation processes (rolling, extrusion, etc.), and not used, to date, in conventional foundry processes. Software for thermodynamic analysis and for the calculation of physical characteristics and viscosity, currently available at the University of Padova, will be initially used. The obtained data will be validated and verified through experimental laboratory tests using the most widespread high-temperature thermal analysis (DSC) and rheology (rotational rheometer) techniques. Predictive models of the physical-rheological characteristics of the material will thus be developed as a function of the initial chemical composition.

Task 2: Study and development of a post-rheocasting heat treatment
This activity deals with defining the methodology necessary to develop the post-rheocasting heat treatments, normally used to obtain the optimal microstructural characteristics to maximize the mechanical and chemical properties. Rheocast specimens will initially be made at a laboratory scale using the secondary aluminium alloy developed during Task 1. Before and during the casting phases, the chemical composition of the alloy will be measured using a mass spectrometer, the content of hydrogen dissolved in the liquid bath using dedicated probes, and the density of the metal to evaluate the initial degree of cleanliness of the alloy. The heat treatment will therefore be studied considering the process phases, such as solubilisation, quenching and ageing. After an initial thermodynamic analysis, the impact of the temperature and treatment time in the various phases of the heat treatment process itself will be analysed, at an experimental level, as well as the influence of the cooling rate during quenching on the mechanical properties. Finally, a hot isostatic pressing heat treatment will be studied to evaluate the improvement induced by a reduction of porosity. Predictive models of the mechanical characteristics of the material will thus be developed as a function of the main heat treatment parameters.

Working language

English

Special entry requirements

• lab experience (metallographic preparation of samples, optical and scanning electron microscopy, thermal analysis, standard foundry practice)
• computer skills (software for image analysis, software for thermodynamic calculations)

Duration in months (min-max)

PhD sandwich: 6-12