Laser Powder Bed Fusion von Magnesiumlegierungen

The additive manufacturing process laser powder bed fusion (LPBF) is increasingly used in industrial series production. Compared to other production technologies, LPBF lacks the range of commercially available materials. Magnesium alloys represent one of these unavailable alloys. Nevertheless, lightweight construction and medical applications would strongly benefit from magnesium alloys being used with LPBF, as magnesium alloys are the lightest structural metals and feature both biocompatibility and biodegradability. However, magnesium alloys are difficult to process with LPBF, particularly because of the high vapor pressure at melting temperature, since the interaction of laser radiation and metal vapor can significantly reduce part quality. Within the scope of this work, two suitable strategies for processing magnesium alloys with LPBF are developed. After selecting a suitable powder material, LPBF specimens made of the alloys AZ91 and WE43are analyzed with regard to microstructure and mechanical properties under static load. For both alloys LPBF specimens exhibit a fine microstructure with mostly equiaxed grains in the size of 1-3 μm. For both tensile and compressive loads, strength and ductility are significantly larger than for typical cast components. At the end of this thesis, various technology demonstrators are built to demonstrate the application-related feasibility of LPBF with magnesium alloys