Additive Manufacturing (AM) is now regarded as an established technique. While subtractive methods, like the combination of casting and machining, have inherent limitations, AM has the ability to produce components of virtually any shape. First developed for rapid prototyping only, the method has over the years greatly improved and evolved to produce fully functional parts. The certification of additively manufactured fuel nozzles for General Electric passenger jet engines is probably the most famous evidence of this evolution.

This fantastic recognition did not come easily and was the result of a tremendous amount of work based on trial and error. Early efforts focused on finding the right combination of alloy composition and heat source characteristics to manufacture sound, small, basic shaped specimens with as high density (as little porosity) as possible. Soon after, focus shifted to mitigating residual stresses and deformations in actual components. Solidification and cooling of melted powder, layer after layer, led to accumulation of residual stresses which either caused components to crack during building or substantially deform when being removed from the build plate.