Manufacturing Processes
Research focus
The Peer review has evaluated this group as Excellent
The main research topics addressed by the research group are: - unconventional manufacturing processes: Water Jet and Abrasive Water Jet (WJ/AWJ), Laser Beam Machining (LBM), Plasma Arc Cutting (PAC); - conventional manufacturing processes: Surface Integrity of machined surfaces (SI), Casting and Machining of Composite Materials (CMC). The efforts in each research topic has varied over the reported period (Figure (1)): activities in conventional machining were progressively reduced while new efforts were dedicated to unconventional machining. One of the main goals of the research group is to become the reference research group in unconventional manufacturing processes at Italian level and to play a strong role at international level. The research group strongly believes that to pursue these goals it is of fundamental importance to set up laboratories where the investigated processes are directly available to researchers. WJ/AWJ The WJ/AWJ research activities started more than 15 years ago. They can be divided into two main areas over the reporting period: WJ/AWJ applications and understanding of systems behaviour. The first area covers different and new water jet applications (rapid prototyping, decoating, natural stones cutting, forming). This area was appreciated by the international scientific community and awarded in the main international WJ Conferences. The research area on system behaviour has dealt with measurement of the most relevant signals that are generated by the system aiming to: - evaluate the performance of system components; - monitor their working conditions, also with diagnostic purposes; - explain the process physics; - identify a model of the system. Moreover, special care was dedicated to the analysis of the effect of the system on the machining quality. LBM The research activities in LBM are performed in the Lecco Campus within the SITEC laboratory (www.sitec.lecco.polimi.it). Research activities in this area cover both basic and industrial research. The basic research activities are divided into three main areas: innovative laser processes (mould repair and surface heat treatment with diode laser), applications to advanced and innovative materials (shape memory alloys and metal matrix composites) and laser process modelling (thermal analytical modelling and porosity generation). The industrial research activities are performed in tight connection with the Italian industry, and are mainly focussed on laser heat treatment and on laser welding [MPR-PRF-5/6]. Collaborations with most relevant Italian laser source and system manufacturers are active. In 2005 a research activity on fibre lasers was started, with the installation of the first high power fibre laser in a Italian research centre. PAC The research activities regarding plasma machining are relatively recent. Their main focus has been the plasma arc modelling with the aim to relate the torch characteristics to the energy density distribution of the arc, which is directly connected to cutting performance. Some studies were carried out with leading international researchers of the plasma technology field and led to a significant recent publication. Surface Integrity of machined surfaces This research area was activated by the end of the 90s aiming to fill a gap of knowledge in this filed. In fact, at that time no model was available to predict the residual stresses generated in machining as a function of process parameters. Since residual stresses influence the performances of a mechanical part in exercise, process parameters should be carefully selected. The knowledge gap was actually filled for turning with the identification of a set of empirical models. Moreover, an European research project was joined with the aim to predict residual stresses on turned Ti6Al4V and Inconel 718 turbine disks for aeroplane engines, and cooperations are active with the most relevant engine manufacturers (Rolls Royce, Avio Group, MTU, etc.). The SI research area was recently abandoned in order to fully develop the LBM area. Casting and Machining of Composite Materials In the mid 90s this research area was launched and was dedicated to: i. the study of casting and machining of MMCs (Al alloy with SiC and B4C powder). ii. the analysis of delamination in drilling of Glass Fibre Reinforced Polymers; As for the SI research area, also the MCM are was abandoned in order to fully develop the LBM area.
Dipartimento di afferenza
Docenti afferenti
Full Professors
Michele Monno
Assistant Professors
Massimiliano Annoni
Daniele Colombo
Barbara Previtali
Matteo Strano