Fracture of three-dimensional lattices manufactured by selective laser melting

Experimentation has been performed to measure the fracture behaviour of three-dimensional lattices manufactured using a Selective Laser Melting (SLM) technique. Specimens have been designed using a compact tension (CT) geometry with different lattice orientations and fabricated from a relatively brittle Aluminum alloy. The toughness has been measured and an increase in fracture resistance has been observed during crack extension. The influence of lattice orientation has been demonstrated, which shows that a change in orientation will result in a different crack path, but the effect on toughness is small. Finally, the significance of specimen size on toughness measurement has been investigated using finite element (FE) analysis. The results show that the experimentally measured result have overestimated the fracture toughness of the lattice specimens by approximately 10% due to the insufficiently large specimen size.