Structure design of porous TC4 alloy with excellent mechanical properties prepared by laser-powder bed fusion

Porous Ti6Al4V (TC4) alloy with a hexagonal structure (optimized side lengths of 700 μm and wall thickness ranging from 100 to 300 μm) was designed by finite element method (FEM) and prepared by laser-powder bed fusion (L-PBF) to improve mechanical compatibility. The porous TC4 alloys were composed of α′-Ti and a little β-Ti phases. The increasing wall thickness of the porous TC4 alloy induced the decrease in effective average diameter of grain from 1.97 to about 1.28 μm and the increase of average density of geometrically necessary dislocation (GND) from 4.46 × 1014 to 6.07 × 1014 m2. When the wall thickness was equal to or greater than 200 μm, the porous TC4 alloy exhibited high yield strength (about 550 MPa) and a proper elastic modulus of (14.4–15.4 GPa). This study could provide a reference for the material design of a new porous TC4 alloy with excellent mechanical properties.