Additive manufacturing (AM), also known as “3D printing,” is often touted as
a sustainable technology, especially for metallic components, since it
produces either net or near-net shapes versus traditionally machined pieces
from larger mill products. While machining from rectilinear or cylindrical
mill products is often the case in aerospace, most of the metal parts used
in the world are made from flat-rolled products and are quite efficient in
metal utilization. Additionally, some aspects of the AM value chain, such as
the use of powder that falls outside of the desired size for AM, are often
not accounted for when determining sustainability. Finally, since the first
production AM parts have only recently entered service, the end-of-life
aspect of the AM cycle and the impact of AM on the overall sustainability of
the system have not yet been demonstrated. Therefore, the primary question
regarding the effectiveness of AM as a more sustainable technology for the
mobility industry in general, and for a particular product, needs to be
asked and answered.
This chapter assesses the overall sustainability of several metallic AM
technologies and material combinations—from the feedstock to disposal
lifecycle. Using a series of scenarios, these factors will be compared with
parts made using conventional technologies for both the present and future
(2040) states.