Fabrication and Compressive Deformation Behavior of Gradient Porous Ti-15Mo Alloy Material

Porous Ti-15Mo alloy specimens with support cells (BCC, Kelvin cells) and triple periodic minimum surface (TPMS) cells (Primitive, Gyroid ,Diamond cells) were prepared by laser selective melting. The porosity was evenly distributed (uniform specimen), increasing along the forming direction (vertical gradient specimen), increasing perpendicular to the forming direction (lateral gradient specimen). The compressive deformation behavior of the alloy was studied. The results show that the inclined support or surface of the porous sample would bond more powder, and the forming quality was relatively poor. The deformation mechanism of vertical gradient specimens was layer by layer from the top to the bottom, and the deformation mechanism of lateral gradient specimens was the whole uniform deformation first, and then the local significant deformation occurred and extended to the uniform deformation region. The compressive properties and energy absorption capacity of TPMS cell specimens were higher than those of the support cell specimens. The Diamond cell specimen had the best comprehensive properties. The elastic modulus, yield strength, platform stress and cumulative energy absorption values of lateral gradient specimen were respectively 4.088 GPa, 134.5 MPa, 175.4 MPa, 117.92 MJ·m^-3, and those of vertical gradient specimen were respectively 3.761 GPa, 104.8 MPa, 165.2 MPa, 92.19 MJ·m^-3.