Additive Manufacturing for the Aircraft Industry: A Review

Abstract

Considering the stringent regulations, manufacturing of aircraft parts is often quite complex and time consuming. The multi-million components, multi-tier manufacturing systems and the severe constraints surrounding the sector lead to heavy inventory investments to achieve the just-in-time supply of parts often needed to reduce the airplane ground times. Additive manufacturing evolved allowing for the direct production of complex parts based on digital data with no complex tooling or machinery, a messiah of true just in time production. Appropriate integration of additive manufacturing with the aircraft industry could resolve some of the supply chain and inventory hurdles. Significant progress is already evident in these lines, but the lack of quality assurance attributes and certification standards is hampering the progress. The state-of-the-art of the application of additive manufacturing in the aircraft industry is reviewed in this paper. The supply chain configurations of the aircraft industry, the possible roles of additive manufacturing in relaxing the pressures in the system are evaluated. The application areas, enhanced attributes, and certification standards are critically reviewed and classified. The overall growth in the application of additive manufacturing in the aircraft industry, the main hurdles, and the future possibilities are evaluated and presented systematically, clearly portraying the developments.

Review: The Impact of Metal Additive Manufacturing on the Aerospace Industry

“…Increasingly stringent sets of testing protocols and certification steps have been established by major governing bodies such as the FAA and EASA before clearing any aerospace components for service, depending on the required application [140]. Such certification typically involves the demonstration of the repeatability of the production process and the consistency of the quality of as-fabricated components.…”

“…Industry-leading aerospace manufacturers such as General Electric (GE), Airbus, and Boeing also utilize their close relationships with MRO providers and regulatory bodies to further progress standard developments for AM [140,166]. In 2018, Boeing signed a five-year collaborative agreement deal with Oerlikon, a leading technology group, to focus on developing standards for AM processes and associated materials [167].…”

“…It is believed that currently there are over 100 AM standards available; some of these are listed in Appendix A [140]. The contents of the standards cover a range of aspects, including the structure of the CAD file, model slicing, process conditions, and post-processing procedures.…”

“…As a result, the dependency on large centralized factories and assembly lines is reduced, further contributing to more savings in the overall operational cost. However, such energy savings currently can only be achieved for low-volume production runs, as the AM processes for metal powders consume a large amount of energy [140]. In situations which require minimal material removal, CM can be the most viable option, offering the fastest, least energy-input approach.…”

“…To date, AM manufacturing centers have mostly been located far from the reach of customers. The aerospace industry often facilitates a three-tiered supply chain structure to assure a continuous inflow of products, which include raw material and as-built part suppliers, OEMs, and companies that provide MRO services [140].…”