OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 26 No. 3 2024 Scanning strategy ⅠV (∠ 90 p.p.) T h e E n d Ta b l e 1 As a result of double remelting large melt drops of 0.2–0.5 mm in size were formed on the surface of the layer which led to uneven application of the next powder layer and appearance of non-melts. For this reason it was not possible to build-up a specimen of the required thickness. For this specimen its porosity was not assessed due to impracticality. The graph of average porosity dependence upon the scanning strategy shows that the specimen obtained using strategy III has the lowest porosity value of 0.03 %, see Figure 6. Fig. 6. Dependence of the average porosity of the specimen on the scanning strategy Density is an important indicator for assessing the quality of the parts. A caliper was used to measure the overall dimensions of the specimens: length×width×height, which was 10×10×3 mm accordingly. Using an analytical balance VST-600/10 we measured the mass of the specimens, which amounted to 0.748 g for the specimen obtained using scanning strategy I, and 0.75 g for scanning strategy II. The calculated density of the specimens for scanning strategies I and II was 2.49 g/cm3, and for the specimen obtained using scanning strategy III, 2.5 g/cm3, which corresponds to the density of silumin. Figure 7 shows SEM images and element distribution maps (Al, Mg, Si) of the specimens obtained using different strategies. Aluminum and magnesium are distributed uniformly in all specimens. Silicon in the specimens is distributed in the form of small particles, less than 5 µm in size. Changing the specimen preparation strategy does not change the nature of silicon distribution in the specimens. The structural-phase state and elemental composition were determined for the specimen formed using scanning strategy III. The specimen under study has a grain structure; the microscopic pores are not detected at the magnifications used.
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