Strain-rate dependent material properties of selective laser melted AlSi10Mg and AlSi3.5Mg2.5

Abstract This paper investigates the mechanical properties of two selective lasermelted aluminum alloys (AlSi10Mg and AlSi3.5Mg2.5) under high strain-rate uniaxial loading. Accelerated tensile tests were performed under various strain-rate decades ( . ε = 4.7 × 10-3 up to 250 s-1) to determine the load-speed-specific changes in the mechanical properties. As a result of the primary laser-based shaping process, the microstructure and characteristics change was entirely comparable to the conventional manufacturing of aluminum parts. Based on an ultrafine microstructure, parts achieve high strength along with a brittle fracture behavior. Modifications for applications requiring high ductility (e. g., the crashloaded structural parts of a car body) can be made through specific heat treatment strategies. The experimental results demonstrate that a significant increase in ductility (factors 4-5) with a concurrent decrease in strength can be obtained compared to the as-built state. In high-speed tests, the tensile strength of both alloys rose strain-rate dependently around 10 %, and the elongation at break increased relatively by ≈ 15 % for AlSi10Mg and ≈ 10 % for AlSi3.5Mg2.5.