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

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 Ni2Al3 is the first phase formed during reaction between the Ni and Al foils at 620 °C. The reaction mechanism is such that only Al atoms can diffuse through the Al2O3 films formed on the Al foils, and the Al atoms then transform into Ni2Al3 by reaction with Ni. The Ni and Ni3Al layers in the composites can therefore cooperatively deform through slipping of dislocations in the Ni and Ni3Al layers through the Ni3Al/Ni interfaces. Thus, Ni/Ni3Al multilayer composites exhibit high ultimate tensile strengths and large elongations (1050 MPa and 18.2 pct).