Defects in additive manufacturing and their influence on structural integrity

In addition to a brief overview of powder bed fusion (PBF) process, which is a subcategory of additive manufacturing (AM) technology, various types of AM defects are thoroughly examined in this chapter, as well as their formation mechanisms during the AM process. Porosities, rough surfaces, and thermally generated micro-cracks are examples of defects that might have several underlying causes and differ greatly between different AM fabricated components. Process variables, such as the metallurgical qualities of the powder, the thickness of the powder layer, deformation during manufacture, and variations in the laser beam, may lead to areas not fully melted (lack of fusion defects), spherical voids, keyhole pores, and other issues. Each kind of imperfection affects the mechanical qualities of the final part, weakening and degrading them. How irregularities and imperfections affect the mechanical resistance and how they can be minimized via postprocessing are explained as well in the final part of the chapter. However, this evaluation makes no claim to be exhaustive in any way. Instead, the goal is to act as a springboard for developing a data base that includes the potential influencing factors on defect formation and their impact on the characteristics of the finished part.