A flexible decision support tool for the green selection of additive over subtractive manufacturing approaches

Abstract

To reduce environmental impacts, energy- and resource-efficient manufacturing strategies must be continuously implemented on a global scale. The industrial sector is a major source of greenhouse gas emissions, and ongoing research into more sustainable practices is crucial. Since its birth, additive manufacturing has gained increasing importance, and it has often been claimed to be a green solution. Nevertheless, scholars have been questioning whether it is a truly sustainable alternative to traditional methods, and several comparative analyses have been released. Studies revealed a complex and ambivalent nature of additive technology; actually, the environmental sustainability domain of additive approaches is not well-defined because it depends on the case-specific nature of the developed comparative analyses. This leads to the lack of a generalizable framework and straightforward guidelines for selecting environmentally friendly manufacturing approaches. In the present paper, cumulative energy demand model simplification of additive and subtractive processes was conducted starting from complex and fully analytical formulations. A model, requiring 60 % less input data than full formulation, has been identified for developing a new decision support tool, relying just on the material embodied energy, specific energy consumption of additive process and geometrical characteristics of the component to be manufactured. This tool minimizes, therefore, the computational and data inventory effort. The designed tool has been tested on different materials, additive manufacturing processes and component geometries. Results revealed that the designed tool represents a generalizable framework easy to be implemented and useable for mapping the energy efficiency performance of different metal powder bed additive approaches.