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

Meanwhile laser-based Additive Manufacturing (AM) technologies such as Laser Metal Deposition (LMD) have been introduced in various fields of applications. The latter 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 sub-millimeter structures has gained interest during the several last years. Fabrication of structures with small dimensions requires different process modifications along the process chain. This includes general process strategies but also adjusted system components. The changed process yields material deposition of varying geometries possibly used in aerospace, space, medical technology as well as micro tooling. Additionally, it can be also used for the repair of worn or damaged micro parts. Within this paper, the aforementioned process modifications are shown and demonstrated. In addition, high-speed process observations are discussed and, finally, fabricated parts are analyzed. The latter includes non-destructive 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.