Reaction synthesis of Ni/Ni3Al multilayer composites using Ni and Al foils: High-temperature tensile properties and deformation behaviour

The effects of temperature on the tensile properties and deformation behaviour of Ni/Ni3Al multilayer composites have been systematically investigated. With increasing tensile test temperature from room temperature to 600 °C, the ultimate tensile strength decreased. The ‘abnormal’ strengthening of Ni3Al gave rise to a reduction in the capability for cooperative deformation between the Ni and the Ni3Al layers at elevated temperatures. As a result, the ultimate tensile strength of the multilayer composites decreased at elevated temperatures. A mixture of transgranular cleavage and intergranular failure at relatively low temperatures, and an intergranular failure at elevated temperatures were observed in the fracture surfaces of the Ni3Al layers in the multilayer composites. The splitting of the coarse precipitates along the {0 0 1} planes at 800 °C resulted from the differences in solubility of Al in Ni between room temperature and 800 °C.