Analysis of Material Properties of Additively Manufactured Workpieces Using High-Speed Laser DirectedEnergy Deposition

Additive manufacturing (AM) processes offer significantly increased freedom of design regarding the production of innovative and function integrated components. Although some AM processes, such as laser powder bed fusion, are already used for prototyping, efficient series production is not possible yet. The limiting factor are the low build-up rates of these processes. The novel technology of high-speed laser directed energy deposition (HS L-DED) offers the potential to solve this problem by significantly reducing process times in additive manufacturing. This technology is characterized by very high feed rates (up to 200 m/min). Consequently, extremely increased build-up rates are achieved and thus the potential for economic additive mass production is increased. The high build-up rates are realized by shifting the laser and powder focus, whereby supplied powder particles are already melted before they reach the melt pool on the substrate. This research primarily focuses on the previously unexplored areas of extremely high feed rates and their influences on the process and its results. Hence, an initial process parameter combination is investigated with respect to the resulting material properties. Based on this, a test plan for the systematic investigation of further process parameter combinations is set up with the aid of suitable selected parameter ratios by means of extrapolation. The data obtained will be used to build a database that correlates the process parameters with the achieved process results, in particular the material properties (relative density, microhardness, melt path dimensions). Using this database, optimum process variables for specific applications can be chosen while ensuring high productivity.