The Microstructure and Mechanical Properties of Heterogeneous Structures TA15 Alloy Fabricated by Laser Powder Bed Fusion‐Vacuum Hot Pressing Composite Process

In this work, heterogeneous structures inspired by natural architectures were introduced into TA15 alloy, endowing the alloy with excellent strength and toughness. The 3D porous TA15 skeleton was fabricated by laser powder bed fusion (LPBF). The skeleton was then filled with TA15 powders, followed by the vacuum hot pressing (VHP) treatment. The resulting heterogeneous structure reveals a distinct periodic distribution with coarse‐grained and fine‐grained. The heterogeneous structure exhibits a combination of high strength (1083.56 MPa) and high ductility (19.24%), which are superior to the fine grains obtained by direct LPBF process (1147.4 MPa and 8.11%). The lamellar structure and texture of the skeletal region suppresses the slip, resulting in uneven strain distribution and a higher density of geometrically necessary dislocations, which are the reasons for the enhanced strength and plasticity of the heterogeneous structure.