Categoria: Ph.D. projects

Roberta Della Gatta’s work is focused on the metallization of polymer and fiber-reinforced polymers by means of Cold spray technology, a technique that belongs to the wider family of additive manufacturing. The metallization of the above-mentioned materials is required in order to provide final components that combine the properties of polymers and fibers reinforced polymers, i.e. lightweight and resistance to corrosion, and the properties of the metals, i.e electrical conductivity and thermal protection. To date, this specific application of the Cold Spray technique is at its early stage and a detailed study of the entire manufacturing process is required. For this purpose, the presented doctoral work aims to give a complete knowledge of the Cold Spray process, trying to understand why certain phenomena occur during the process and answer the main unsolved questions about the subject matter. A comprehensive analysis of the entire process is proposed, starting from the manufacturing of the main components, going through the optimization of the cold spray process parameters to the assessment of the potential environmental impacts associated with the materials and energy inputs. The objective is to provide guidelines for the manufacturing of customized polymer/composite components and to identify the best technology suitable for further cold spray application. Likewise, the estimation of the environmental impacts associated with the final products is crucial to compare the Cold spray process to other coating techniques, establishing an inventory of environmental releases.

Valerio Lampitella’s doctoral research project focuses on the study of powder handling in powder bed based Additive Manufacturing technologies. His research aims to understand and optimize the spreading mechanism in order to obtain more reliable and overall higher quality 3D printed products. 

He uses a combined experimental and numerical approach through the use of a custom designed experimental device able to faithfully replicate the conditions in an actual 3D printing machine and with the use of a software particularly suited for the simulation of complex granular systems (LIGGGHTS). With such a combined approach the process can be studied on both a particle-scale and full-scale. 

Most of the scientific literature on the topic focuses on the optimization of the laser processing parameters and strategies, often overlooking the powder bed characteristics. However, some of the longstanding issues in Laser Powder Bed Fusion Additive Manufacturing techniques can be attributed to an unevenly layered powder bed. Moreover, this uncertainty does not allow for a complete optimization of the process. 

The final objective will be the definition of the layering of the powders as an independent sub process, linking the process parameters to the powder bed characteristics and, ultimately, optimizing it to obtain better mechanical properties of the manufactured parts, with a significant impact on the sustainability of the process via the reduction of the energy output required and enabling the recycling of the powders.

Industrial Products and Processes Engineering XXXVI Cycle

Ersilia Cozzolino’s doctoral research project focuses on the study of sustainability of Additive Manufacturing processes. Her research aims to understand how to produce products through Additive Manufacturing technologies that meet, on the one hand, quality requirements for industrial applications, and, on the other, environmental ones. In particular, the research purpose is to understand how to vary the parameters of additive processes in order to obtain products with good mechanical properties with a low impact on the environment and what could be useful indicators to evaluate the sustainability of processes.
It is known in the scientific literature as well as in industrial production that products fabricated with Additive Manufacturing processes can’t be used as-built but require post-processing phases by using traditional technologies, whose processes have an impact on the environment as well. Therefore, the research activity not only looks at the sustainability of the Additive Manufacturing processes but the entire production cycle to obtain the product, and therefore also the post-processing phases that are necessary to obtain a surface finish of acceptable products. During the experimental activities, therefore, the energy consumption and consumption of resources will be monitored in order to obtain useful results that hopefully help industrial companies to rethink the processes in a sustainability perspective. 
The final objective will be, on the one hand, to fill the gaps of knowledge present on the subject in the scientific literature, and thus contribute to the dissemination of new knowledge, and on the other hand, provide guidelines to the industrial world, where sustainable production will become imperative in the coming decades.