Paper Title
Main Limitations and Problems in Additive Manufacturing Process for the Aerospace Industry

Abstract
Additive manufacturing (AM) processes, also known as 3D printing, are relatively recent rapid prototyping technologies which are associated with layer-by-layer fabrication to produce three-dimensional objects. AM processes offer the production of complex-shaped and lightweight production, which is not possible to achieve by using conventional manufacturing processes. Because of this capability of AM processes, this technology is broadly used in the aerospace industry where mass efficient complex-shaped components are demanded. In this regard, AM processes are ideal methods to produce unique-shaped and lightweight aircraft components and bodies with high quality and structural integrity. However, AM processes for the aerospace industry have several limitations and problems deriving from both some characteristic features of AM processes and hard to achieve aerospace industry requirements. Even though the adaption to AM processes in the aerospace industry is progressing, the use of recent AM processes for the aerospace industry is still limited due to several factors. Some of the main examples of these factors are; metallurgical defects occurring during the thermomechanical cycles of materials being printed, lack of globally recognised standards and certifications, cost of AM processes in the production of aircraft components resulting from some reasons such as surface finish necessity, low production speed compared to conventional manufacturing processes, limitation of production size, the inability of meeting pack delivery time, challenges in mechanical testing of additively manufactured as-fabricated aerospace components and unachievable high manufacturing precision demand. These main limitations are discussed in this study. Keywords - Aerospace Industry, 3D Printing, Additive Manufacturing, Light weighting