Mechanical Properties and Deformation Behavior of a Nanostructured Aluminum Alloy Toughened by Titanium Alloy Base Three-Dimensional Lattice Structure

Lightweight structural materials with excellent strength and good ductility are extensively used in engineering applications. Although nanostructured Al alloys have relatively low density and high strength resulting in high specific strength, their application is severely limited due to their poor ductility. Recently, additive manufacturing (AM) techniques have been rapidly developed and complex lattice structures can be manufactured by AM. Here, a new composite containing titanium alloy lattice structure and nanostructured Al alloy was created. Selected laser melting is used to generate the TC4 three-dimensional lattice structure, which is subsequently hot extruded with the high-strength nanostructure Al84Ni7Gd6Co3 aluminum alloy. Tensile mechanical characteristics and fracture behavior were studied. The research results reveal that the TC4 lattice structure in the composite remains intact and the interface remains flat and clear, and the alpha and beta phases are elongated along the extrusion direction to form a fine lamellar structure. There is a significant volume proportion of nanostructured intermetallic phases and nanocrystalline fcc-Al in the nanostructured aluminum alloy areas. The mechanical property test results reveal that the TC4 three-dimensional lattice structure has a clear limiting influence on fracture initiation and propagation in the nanostructured aluminum alloy region, resulting in good comprehensive tensile mechanical properties of the composite.