Ersilia Cozzolino

Machining operations represent a major source of industrial energy consumption, especially when components are produced through multi-stage process chains. However, most existing studies focus on individual machining operations rather than the integrated behavior of sequential processes. This study investigates a machining chain consisting of internal turning, surface milling, and drilling performed on C40 carbon steel components. A wide experimental campaign was conducted, with real-time monitoring of electrical current and voltage to determine instantaneous power and cumulative energy consumption. A data-driven framework was developed to predict total specific cutting energy and total machining time using only primary machining parameters. The modeling procedure included rigorous data preprocessing, prevention of data leakage, cross-validation, hyperparameter tuning, and external validation. Ensemble learning models achieved high predictive accuracy, enabling reliable estimation of global energy and time indicators. The proposed approach supports virtual sensing and energy-aware process planning in sustainable manufacturing systems.

Composite structures are increasingly being used across a wide range of industries for applications that require optimised mechanical performance and reduced weight. As the demand for innovative materials grows, research into composite structures manufactured through additive manufacturing is gaining increasing attention, especially with the fused filament fabrication (FFF) technique. In this context, PLA+flax composites printed by FFF are gaining attention for their enhanced mechanical properties and sustainability under specific circumstances. A critical factor affecting the mechanical performance of PLA+flax composites is part thickness, particularly in terms of low-velocity impact resistance. Thicker parts generally offer higher impact resistance and structural integrity, but the challenge for FFF parts lies in optimizing thickness alongside other variables, such as infill strategy. Although several studies have investigated the influence of infill topology or mechanical behaviour of FFF biocomposites, fewer works have simultaneously examined the combined effects of thickness, infill architecture and printing energy consumption for PLA/flax systems. This study demonstrates that increasing thickness does not necessarily improve mass-normalised mechanical performance nor energy-normalized efficiency in FFF PLA+flax composites unless coupled with infill architectures capable of efficient shear transfer. Among the investigated configurations, the 6 mm gyroid structure exhibited the highest penetration energy (16.07 J), slightly outperforming the fully solid configuration despite a lower material fraction. Furthermore, the volumetric specific energy consumption decreased from approximately 66.9 kJ/cm ³ for 2 mm specimens to 25.9 kJ/cm ³ for 6 mm specimens, indicating a substantial improvement in manufacturing efficiency with increasing thickness. Overall, gyroid and hexagonal architectures provided the most favourable balance between impact resistance, lightweight efficiency and energy consumption.

Sheet metal forming processes are widely used across various industries and account for a significant portion of energy consumption in manufacturing. With sustainability becoming a growing focus, researchers are exploring more energy-efficient methods for metal forming. One promising approach is electrical-assisted forming, particularly treatments based on electroplasticity (EP) effects, which can deform metals at lower temperatures and with reduced loads. Among these, pulsed current-based treatments have emerged as a viable alternative to traditional furnace heat treatments, offering significant benefits in terms of process sustainability. This study proposes an innovative pulsed current treatment to reduce the flexural strength of cold-rolled titanium sheets, enhancing their formability and reducing the loads required during sheet metal forming. An extensive experimental campaign was conducted, varying parameters such as current density, number of pulses, grain orientation, and pulse frequency. The effectiveness of the treatment was evaluated by measuring the flexural strength of the specimens, while microstructural analyses were performed to understand the impact of the electric current on the material’s internal structure, particularly in terms of dislocation rearrangement and annihilation. The results demonstrated the effectiveness of the proposed treatment, achieving up to a 19% reduction in flexural strength. This also provided new insights into the complex interaction between electric current and plasticity, an area that remains unclear and is still a subject of ongoing debate.

Modern manufacturing increasingly demands energy-and resource-efficient solutions. Conventional metal forming often requires high temperatures to reduce flow stress, resulting in high energy consumption, especially for low-formability alloys. Electrically-Assisted Manufacturing (EAM) has emerged as a promising alternative, leveraging the electroplastic effect, i.e. electricity’s direct influence on plastic deformation. Documented benefits include reduced forming forces, improved ductility, and altered fracture modes. Indeed, integrating electroplasticity into manufacturing aligns with Industry 4.0 and decarbonization goals, enabling lower energy consumption, extended tool life, and greater compatibility with renewable energy sources. This study compares conventional tensile testing and electro-assisted tensile testing (EAM) of Ti6Al4V, evaluating both mechanical results and the energy consumption of the testing machine under different conditions. The comparison results highlight the potential of pulsed current to improve material formability while reducing energy consumption, offering a more sustainable approach to manufacturing.

Electroplasticity in sheet metal forming is a relatively recent method that involves applying an electric current to metal sheets during or before the forming process. Existing research on Electro-Assisted (EA) forming primarily focused on material characterization; few studies have investigated the effect of electropulsing on loads, power, and energy consumption during sheet metal forming, and no studies have explored the reshaping of previously formed titanium sheets after the Electro-pulsed treatment (EPT). This research aims to bridge some of these gaps of knowledge by applying two different electropulsing treatments, varying in current density, to square Ti6Al4V specimens prior to shaping and reshaping. performed using dies and counter dies having different geometries. Load, power, and energy consumption data were measured to assess the benefits of EPT compared to an untreated specimen serving as a reference. The findings suggest that EPT can significantly reduce the energy consumption and forces required for both shaping and reshaping of titanium components, extending their useful life and reducing the need for remelting. The study highlights the potential of EPT as a sustainable solution for reducing the environmental impact of titanium sheet disposal and recycling, improving material efficiency, and optimizing industrial forming processes.

This work focuses on the pultrusion of pre-consolidated tapes made of virgin polypropylene reinforced with glass fiber. A specially designed laboratory-scale pultrusion line was used, consisting of a heating/forming mold, a cooling mold, and the pulling system. A life cycle assessment was conducted to evaluate the environmental impact of producing a pultruded composite material with a constant cross-section of 100 mm² and a length of one meter. The cradle-to-gate approach was chosen to model the pultrusion process, which involves the three stages mentioned above. The analysis was performed using the CML 2016 method in the LCA for Experts (Sphera) software. The data used in this work to model the cradle-to-gate scenario are mainly derived from experimental measurements taken during the pultrusion process using sensors and from the literature. The specific Energy Consumption (SEC) was calculated for both operational conditions (1.41 MJ/m at v120 to 0.905 MJ/m at v180). Despite the defects found, the samples taken from the pultruded profile showed significant interlaminar shear strength (120 mm/min of 83.7 ± 9.6 MPa compared to 63.5 ± 17.3 MPa at 180 mm/min).

Sustainable manufacturing is increasingly vital in reducing the carbon footprint of energy-intensive industries. In this context, aluminium alloys, commonly used in food packaging applications such as food trays and wine caps, have a significant carbon footprint due to the energy-intensive electrolytic process used in primary production. Few studies have investigated the combined effects of higher percentages of secondary aluminum on both the environmental impact and mechanical properties of semi-finished products in the packaging industry. To bridge that knowledge gap, this work, conducted in collaboration with Laminazione Sottile S.p.A., investigates the potential of a new aluminium alloy, with a high manganese content and 80% secondary aluminium, on the environmental impact and mechanical properties of food trays and wine caps. For this purpose, a cradle-to-gate Life Cycle Assessment (LCA) and tensile tests were performed to assess, respectively, the environmental and mechanical performance of the above-mentioned semi-finished products. Results show that replacing the conventionally employed alloys with the new one can lead to up to 55% reduction in Global Warming Potential (GWP), Depletion of abiotic resources-fossil fuels (ADPf), and Photochemical Ozone Creation Potential (POCP). Mechanical tests also confirmed that the new alloy can even increase the Ultimate Tensile Strength (UTS), up to 4.2%, and yield strength, up to 18.2%. A sensitivity analysis also highlighted that the increase in the percentage of secondary aluminum has a greater environmental benefit than switching to renewable energy alone, although both strategies enhance performance. In fact, the most substantial environmental increase occurs when the percentage of secondary aluminum is reduced from 80% to 60%, regardless of the energy source, emphasizing the critical role of secondary aluminum in minimizing the overall environmental footprint. These findings provide a viable pathway for the aluminum industry to reduce carbon footprint in packaging applications without compromising product performance, supporting the industry’s transition toward decarbonization and net-zero targets by 2050.