Исследование структуры и свойств сплава AlSi10Mg, полученного методом селективного лазерного сплавления

Abstract

The paper investigates the structure and properties of samples made of ASP-25 AlSi10Mg, a Russian powder designed to replace expensive additive manufacturing powders of European origin featuring the same chemical composition. We detected that the particle size in the ASP-25 AlSi10Mg powder varies in the range of 7 to 50 μm, the average particle size being 23 μm for the standard deviation of 9.15 and dispersion of 83.7. On the surface of powder particles, we observed smaller satellite particles, individual aggregates, and particles of pure aluminium. We detected the following at the transition boundary between adjacent tracks: a columnar crystal zone and a heat-affected zone consisting of three layers of large, medium and small grains generated as a result of varied cooling conditions. These grains display different silicon lattice thicknesses along their boundaries. We detected no critical size pores (over 15 μm) or burning in the heat-affected zone. The fact that microhardness increases towards the sample edges and is non-monotonic over the transverse section is due to a range of factors acting simultaneously to create non-uniform temperature and force fields that cause differences in conditions of structure formation. Fractography studies of fractures in the AlSi10Mg alloy showed that the nature of failure varies along the sample depth. The central part of the sample, which is subjected to the highest thermal effects, shows clear signs of viscous failure along the main cracks developing along the boundaries of construction layers. We showed that the AlSi10Mg alloy is more resistant to pitting corrosion and general corrosion than the AK9сh (AK9ч) alloy