Dynamic response of AlSi10Mg alloy fabricated by selective laser melting

The dynamic response of selective laser melting (SLM)-processed and sand cast Al10SiMg samples were studied in a series of planar impact experiments. It was found that the dynamic response of SLM-processed alloys is virtually independent of the processing orientation. The dynamic yield strength and tensile (spall) strengths of SLM-processed material exceeds those of the cast alloy by factors of two and four, respectively. It was found that with increase in the tensile strain rate ε̇_t, the fracture mode of SLM-processed material changes from apparently ductile at strain rates below ε̇_t≈5×10³s⁻¹ to evidently brittle above this threshold. At approximately the same strain rate and at shear stress greater than 65 MPa, the mechanism governing the compressive (yield) strength of the SLM-processed alloy also changes from thermally-activated passage of obstacles by moving dislocations to dislocation over-barrier glide controlled by phonon viscous drag.