Synthesis of a three-component aluminum-based alloy by selective laser melting

Introduction. The technology of selective laser melting is one of the key technologies in Industry 4.0, which allows manufacturing products of any complex geometric shape, reducing significantly the amount of material used, reducing the lead time and obtaining a new alloy from elementary powders in the melting process. To understand the process of alloy formation under laser exposure, it is necessary to know the initial data of powders, which significantly affect the quality of the products obtained. The purpose of this study is to determine the requirements for the structural-phase state, elemental composition of aluminum, silicon and magnesium powders and further preparation of Al-Si-Mg (Al — 91 wt.%, Si — 8 wt.%, Mg — 1 wt.%) powder mixture for laser synthesis. The initial powders of aluminum PA-4 (GOST 6058-73), silicon (GOST 2169-69) and magnesium MPF-4 (GOST 6001-79) and powder composition Al-Si-Mg are studied using X-ray diffraction and X-ray phase analysis. The shape and sizes of particles are determined by the studies of raster electronic images. By the method of selective laser melting, samples are obtained from a powder composition under constant and pulsed laser exposure. The composition is prepared by mixing powders in a globe mill. Results and discussion. It is shown that the initial powders of aluminum, silicon and magnesium are single-phase. Particles with a size of 20–64 µm, recommended for selective laser melting, are used to obtain a powder composition. By mixing the powders for one hour, spherical particles are obtained, which is preferable for laser melting. The results of grinding the samples after laser melting showed that the samples obtained under constant laser exposure at the following mode parameters: P = 80 W, V = 300 mm/s, s = 90 μm, h = 25 μm have the greatest mechanical strength. Conclusions. The described study shows the possibility of synthesizing products from a powder composition of aluminum, silicon and magnesium by selective laser melting.