Plastic damage of additive manufactured aluminium with void defects.

Highlights • The plastic deformation of the crystal firstly appears around the void, that is, the slip systems around the void start first. • The single crystal with the hard orientation and the bicrystal with the larger misorientation between the two grains are more difficult to slip. • The slip systems in crystal with a circular pore are more prone to start than with an elliptical pore. • The loading direction that is vertical to the grain boundary is more conducive to the slip of the crystal and the growth of the pore. Abstract Additive manufacturing technology is a novel approach for the development of the modern industry. Additive manufactured aluminium (Al) becomes the hotspot of current research in order to achieve the high-precision products. However, the additive manufactured Al parts easily generate void defects due to the poor fluidity and low density of the materials, which in turn affects the mechanical properties. This paper studies the damage behavior of additive manufactured Al parts with void defects under tensile load in a mesoscale by using a two-dimensional rate-dependent crystal plasticity theory. The stress-strain curves and the plastic damages of single crystal and bicrystal with void defects are determined with different combinations of crystal orientations and loading conditions. It is found that the mechanical properties of additive manufactured aluminium severely depend on the crystal orientations and shapes of void defects. [ABSTRACT FROM AUTHOR]