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 et, the fracture mode of SLM-processed material changes from apparently ductile at strain rates below (epsilon) over dot(t) approximate to 5 x 10(3) s(-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.