Effects of the Build Direction on Mechanical Performance of Laser Powder Bed Fusion Additively Manufactured Ti6Al4V under Different Loadings

Laser powder bed fusion (LPBF) of Ti6Al4V, one of additive-manufactured titanium alloys, has a great potential to be applied in aviation structural components. At present, the fracture behaviors of Ti6Al4V manufactured by LPBF under different loading conditions, especially under torque, bending, and shear loading, is still insufficient. To meet this demand, three different build direction samples (0° sample, 45° sample, and 90° sample) are designed herein. Four different mechanical testing (compression, three-point bending, double shear, and torsion testing) are carried out. Load versus displacement curves and torque versus twisting angle curves are measured and studied. Fracture surfaces are compared and analyzed. It is shown that the 45° sample has the highest compressive Young's modulus (136 GPa) and the 90° sample has the highest flexural strength (948 MPa). The ultimate compressive displacement of the 0° sample is 1.84 times larger than that of the 90° sample. And the bend angle of the 90° sample is 1.95 times larger than that of the 0° sample.