R-Curve characterization of the fracture toughness of nanocrystalline nickel thin sheets

The fracture resistance curves of nanocrystalline nickel and carbon doped nanocrystalline nickel for different annealing temperatures have been generated and studied. The results indicate that crack growth resistance of pure nanocrystalline nickel is very sensitive to annealing temperatures. The crack growth resistance decreased with increasing annealing temperature for the nanocrystalline nickel. Carbon doping greatly reduces crack growth resistance of nanocrystalline nickel. However, the crack growth resistance of carbon-doped nanocrystalline shows improvement through annealing processing. A cluster model was used to explain the crack growth resistance behavior of nanocrystalline nickel.