No abstract

No abstract

No abstract

Selective electron beam melting (SEBM) is perhaps the fastest production process for additive manufacturing techniques from powder beds. In the present investigation, scan speeds of 10 m s À1 have been used successfully for the melting. Nevertheless, the beam power has to be adjusted to guarantee a density of more than 99.5% for the build samples. The aim of this paper is to investigate the effect of the scan speed and beam power on the microstructure and the mechanical properties of Ti-6Al-4V. Therefore, a process map with a window for samples with a density higher than 99.5% and a good geometrical accuracy was developed. But, there are strong differences in microstructure and the resulting mechanical properties. These differences result from changes in the total energy input. In the presented work, strength is found to increase somewhat with decreasing volume energy (60-30 J mm À3 ) at a scan speed of 4 m s À1 as the cooling rate increases. This causes a change in microstructure, as the a platelet size varies in the range between 400 nm and 1.3 mm. Thus, an increase in ultimate tensile strength of 5% could be realized by adjusted energy input.

Within this paper the characterization of hybrid components consisting of selective electron beam melting (SEBM) additive structures and sheet metal of alloy Ti-6Al-4V will be presented. Key idea of the new production approach is the combination of the advantages of two different manufacturing processes. On the one hand the very high flexibility of the additive manufacturing process and on the other hand the economic production of conventional geometries by deep drawing operations. Main challenge within this new and innovative process is the identification and quality of the properties of the new hybrid components after the manufacturing process. The necessary evaluation consists of three parts: the analysis of the deep drawing blanks, the additive manufactured structure and finally the connection between both. Whereas standardized testing methods are available for the testing of the blanks and the additive structure, there are hardly scientific publication which deals with the investigation of the connection between them. Therefore, a new testing methods and consequently a new tool design was developed in order analyze the specimens in dependency of different strain- and stress conditions. At the end microstructural investigations were performed to identify the fundamental mechanisms which lead to the different properties on macroscopic scale. The result proofed that in particular the electron beam power has a high influence on the production process and thereby the connection quality.