High strain rate investigation on the mechanical anisotropy induced by SLM technology on a 3D printed steel

Selective Laser Melting (SLM) technology is an additive manufacturing (AM) technique that involves selective or localized melting of metallic powder bed by a high-intensity laser beam source. This technology is responsible for an induced anisotropy in the printed components: in fact, depending on the orientation of the part within the powder bed, different mechanical properties are usually obtained. It is also known that mechanical properties may depend on the rate of load application. This work studies the mechanical anisotropy induced by SLM technology on a 16MnCr5 case hardening steel subjected to high strain rate loading. A direct Split Hopkinson Bar was employed for testing. The Cowper-Symonds model was used to describe the material behavior at high strain rates for samples loaded in the building and in the normal to building directions.