Comparative life cycle assessment of two different manufacturing technologies: laser additive manufacturing and traditional technique

Additive manufacturing processes, such as Laser Additive Manufacturing (LAM), has become increasingly established in metal-processing industry offering versatile possibilities for producing individualized components or lightweight structures. LAM machines offer ecological and economical potentials due to comparatively low power and material demand. In general, Additive Manufacturing (AM), has been considered an alternative to the traditional manufacturing techniques, such as Subtractive Machining (SM), because allows the creation of new, light and complex products with an innovative design and manufacturing. Sustainability assessment is essential to identify and select the best technology among the alternative candidates. Sustainability of LAM needs to be evaluated for finding an optimal compromise between technical development and sustainability performance. The Life Cycle Assessment (LCA) methodology is applied to investigate the sustainability of Laser Engineered Net Shaping (LENS) by comparing that of the Computer Numerical Control (CNC) machining. The aim of this research is to analyze and compare the environmental impact between additive and subtractive manufacturing. In particular, CNC (SM) and LENS (AM) technologies have been chosen. A common spur gear has been defined as a case study. Therefore, the analysis allows to define the ecological characteristics of a new production technology compared to a gold standard such as CNC machining. Hence, the advantages and disadvantages of the reviewed additive technology are exposed. The ReCiPe midpoint results, shows advantages in term of environmental impact for the LENS manufacturing process, in particular for the damage to resource indicator.