Mechanical Properties of a Layered Ti–6Al–4V Alloy Composite Material Fabricated under Low-Temperature Superplasticity Conditions

Abstract The mechanical properties and structure of a layered composite material based on a Ti–6Al–4V alloy and fabricated by diffusion welding of plates with different grain structures are studied. The outer plates of the material have a microcrystalline structure, and the intermediate plate (reinforcing element) has a nanocrystalline structure. At a welding temperature of 900°C, grain growth to microcrystalline sizes is found to occur in the intermediate layer. Welding at 700°C does not change the grain size in the reinforcing element, and the grain size of the α phase increases slightly as compared to the initial one. The strength of the composite material formed at 700°C can exceed the strength of the composite material formed at 900°C. The scheme of fracture of the composite material in the solid-phase joint zone during a room-temperature tensile test is studied.