An Investigation of the Effect of Sintering Conditions on the Mechanical Behavior of Electroplated Nickel Foams

This study investigates the effect of sintering temperature on the compression strength of nickel foams in an inert atmosphere. The nickel foams were produced by the electrodeposition technique on polyurethane foam substrate. As-plated Ni foams were sintered at 873 K, 1073 K, and 1273 K (600 °C, 800 °C, and 1000 °C) in order to eliminate polyurethane and to enhance ductility at a controlled atmosphere. A compression test was used to determine the mechanical behavior. The morphology of produced foams was analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) techniques. Quantitative EDS analysis implied that carbon diffuses into nickel structure during the polyurethane decomposition. The amount of carbon in nickel foam increases with heat treatment temperature. The results also reveal that the oxygen impurity arisen from polymer vapors can diffuse into the nickel structure at elevated sintering temperature [i.e., 1273 K (1000 °C)]. The compression curve of as-plated foam showed brittle behavior due to the electroplating condition. The sintering process in the neutral atmosphere could create ductile foams, although the strength of the foams decreases with an increase in the sintering temperature.