Superplastic deformation behaviour of electrodeposited nanocrystalline nickel

In this paper, the superplasticity of an electrodeposited nanocrystalline nickel with a grain size of 65 nm was examined under different strain rates and temperatures. A maximum elongation of 550% was obtained at a relatively low temperature of 450 degrees C and a strain rate of 1 center dot 67 x 10(-3) s(-1). The strain rate sensitivity index is found to be >0 center dot 5 demonstrating its good superplasticity. The fracture surfaces and the deformed microstructures reveal that significant grain growth occurs during deformation, and it is found that the addition of SiC particles can effectively improve the superplasticity of the material. Experimental results further illustrate that the deformed microstructure is dependent on the strain rate, and the surface morphology of the material is relating to its oxidation phenomenon during deformation.