The Compressive Behavior of Porous TC4 Alloy Scaffolds Manufactured by Selective Laser Melting

Abstract

Porous TC4 alloy scaffolds with curved struts were fabricated by selective laser melting (SLM), and the compression deformation behavior of the TC4 alloy scaffolds was studied. When the porous scaffold is compressed along the direction of the building, the stress of the porous scaffold first increases sharply with the increase in the strain, then decreases rapidly and finally shows a stepped increasing trend. Combined with the finite element method and uniaxial compression experiments, the shear position of porous scaffold takes precedence over other parts, and the fracture mainly occurs on the strut near the joint of the porous scaffold. The fracture surface analysis shows that the joint is a ductile fracture, and there is a shallow “dimple” pattern of shear or tear type on the fracture surface, while the fracture morphology of the strut near the joint of porous TC4 alloy scaffold is relatively smooth, which is a typical brittle fracture. The mixed fracture mode is caused by the more concentrated stress at the strut than the joint and the hexagonal close-packed (hcp) fine martensite α′ formed by the SLM.