Project Details
Projekt
In-situ alloy variation in laser powder bed fusion processes
Subject Area
Materials in Sintering Processes and Generative Manufacturing Processes
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 455584331
The in-situ alloy variation in Laser Powder Bed Fusion (LPBF) for the generation of variable alloyed samples with the same starting powder material within a production process shall provide an extremely flexible method for alloy development or the generation of graded materials. The method should be able to produce homogeneous samples with a specifically adjusted alloy content as well as graded samples with areas of low and higher alloyed areas. The project is based on the approach of a combined process of suspension printing technology and laser beam (re)melting in a powder bed. First, carbon is used as the alloying element, which is added by means of suspensions via a print head during the process. For an efficient local homogenization of the alloy composition after adding the additional amount of carbon, an approach based on the method of laser deep alloying shall be applied. The flexible application of the carbon by means of suspension deposition shall take place after the fusion of one powder layer and before the application of the next powder layer. The applied amount of carbon must be dried, (fixed) and remelted in different depths for homogenization. The deep alloying process should make it possible to homogenize several standard consolidated powder layers with regard to the carbon content at the same time so that the required increase in process duration compared to the standard LPBF process is minimized. The main mechanisms influencing homogeneity shall be identified, understood and predicted on the basis of flow simulations and experimental data. The influencing factors are mainly seen in the strongly pronounced melt pool flows in keyhole processes, in possible diffusion processes due to heat accumulation in the previous component layers during a continuous process and in the formation of melt splatter and gas flows.
DFG Programme
Research Grants
Co-Investigators
Professor Dr.-Ing. Axel von Hehl; Professor Dr.-Ing. Frank Vollertsen
