PROPERTIES OF THE RS-553 ADDITIVE ALUMINUM ALLOY AT STRAIN RATES OF UP TO 10⁴ sˉ¹

Abstract

Data have been obtained on the properties of the aluminum-magnesium-scandium alloy grade Rusal RS-553, manufactured using the additive technology of selective laser melting, at strain rates of up to 4,5∙10³ sˉ¹. Selective laser melting technology, combined with topological optimization, offers unique capabilities for producing complex bionic structures, including internal structures and lattice elements unattainable by traditional manufacturing methods, and also allows for a significant reduction in component weight while maintaining the required strength characteristics. The corrosion-resistant, high-strength RS-553 alloy is produced by melting a powder composition whose main chemical elements are aluminum, magnesium and scandium with a high-power laser beam. This composition was specifically developed for manufacturing components using additive technologies. The test specimens were cut from cylindrical blanks grown in the direction of the laser beam scanning. Dynamic compression tests were conducted using a split Hopkinson pressure bar setup at strain rates in the range of (2,4-4,5)∙10³ sˉ¹. Unlike the method of recording bar strain using strain gauges, an optical laser heterodyne interferometry technique was employed in the experiments with the investigated specimens. In the tests, the surface velocities of the bars were recorded, and the conversion to strain was performed taking into account the speed of sound in the bars, as well as the tilt angle of the optical sensors aimed at their ends. The properties of the RS-553 alloy, determined from the compression tests, were compared with those of aluminum alloyscontaining magnesium, AMg6 and D-16T, produced by traditional casting technology. Based on theobtained results, within the considered loading rate range, the compressive yield strengths of the RS-553 and D-16T alloys are practically identical and are approximately 1.5 times higher than the yield strength of the AMg6.