Speaker
Description
In the last decades alternative production methods for alloys have become the focus of science and industry. One of these production methods is using laser powder bed fusion (LPBF), in which alloys can be printed in complex, delicate and hollow shapes and geometries, which is difficult for the conventional casting and forging approach. The 3D printable alloys are used in the area of transportation and industry.
A cooperation (BMFTR project “AlaAF”) was started between Colibrium Additive, Friedrich-Alexander Universität Erlangen-Nürnberg and Technical University of Munich to improve the printing properties of aluminum alloys with added “reactive additive manufacturing” (RAM) particles. Printing aluminum alloys using the LPBF method led to large, columnar grains in build direction, which in particular for conventional high-strength and forging alloys cause internal residual stress, anisotropic mechanical properties and higher probability of crack formation. To prevent this crystal growth RAM particles are added, which react during the printing process and form ceramic particles inhibiting the growth of the Al grains.
X-ray diffraction (XRD) and neutron diffraction (ND) experiments were conducted on the raw powder and consolidated material after the printing process and heat treatment to follow the phase changes. ND enables the detection of light element phases such as B4C even in real bulk samples (up to cm3), which can’t be observed using XRD due to the low electron count of these elements and the small beam size. Besides phase compositions, diffraction experiments can also be utilized to investigate the microstructure of the materials alongside the crystallite size and crystal structure defects analysis.
