Fracture and failure behavior of additive manufactured Ti6Al4V lattice structures under compressive load

Abstract The additive manufacturing technology can be used to manufacture the complex lattice structures that are difficult to be fabricated by the traditional manufacturing technologies. In order to study the fracture and failure behavior of Ti6Al4V lattice structures manufactured by selective laser melting under compressive load, the cell topologies of face centered cubic with vertical struts (FCCZ) and body centered cubic with vertical struts (BCCZ) were chosen. The bulk material samples and four kinds of FCCZ and BCCZ lattice samples were designed and manufactured. The compression tests were performed and progressive failure modes were studied and compared. And stress–strain curves, the compressive strength, the effective elastic modulus, and the specific compressive strength were calculated and compared. It is shown that the compressive strength of FCCZ samples is about 30% higher than that of BCCZ samples. Both 30 mm and 50 mm FCCZ samples exhibit abrupt shear failure, while the local buckling of lattice cells is the major failure mode for both 30 mm and 50 mm high BCCZ samples. Finite element analysis was conducted to study progressive damage of the lattice samples, and the numerical results can explain the experimental findings.