Reaction Synthesis of Nickel/Aluminide Multilayer Composites Using Ni and Al Foils: Microstructures, Tensile Properties, and Deformation Behavior

摘要

Full-density nickel/aluminide multilayer composites were successfully fabricated by reaction synthesis using Ni and Al foils. The Al is the dominant diffusing species, and Ni_2Al_3 is the first phase formed during reaction between the Ni and Al foils at 620 deg C. The reaction mechanism is such that only Al atoms can diffuse through the Al_2O_3 films formed on the Al foils, and the Al atoms then transform into Ni_2Al_3 by reaction with Ni. The Ni and Ni_3Al layers in the composites can therefore cooperatively deform through slipping of dislocations in the Ni and Ni_3Al layers through the Ni_3Al/Ni interfaces. Thus, Ni/Ni_3Al multilayer composites exhibit high ultimate tensile strengths and large elongations (1050 MPa and 18.2 pct).