Process characteristics in high-precision laser metal deposition using wire and powder

Laser-based additive manufacturing (AM) technologies such as laser metal deposition have been introduced in various fields of applications. Laser metal deposition is not only used for the fabrication of complete new parts but also for the purpose of repair and redesign. Therefore, weld beads with dimensions above 1 mm were mostly used in the past. In some cases, bead widths can even exceed 10 mm or more. However, the build-up of filigree parts by means of submillimeter structures has gained interest during the last several years. Fabrication of structures with small dimensions requires different process modifications along the process chain. This includes not only general process strategies but also adjusted system components. The changed process yields material deposition of varying geometries possibly used in aerospace, space, medical technology, and microtooling. Additionally, it can also be used in the repair of worn or damaged microparts. In this paper, the aforementioned process modifications are shown and demonstrated. In addition, high-speed process observations are discussed and, finally, the fabricated parts are analyzed. The latter includes nondestructive and also destructive methods. Based on the combination of changed process elements, a stable laser-based AM procedure is presented, which is already in production.