Enhanced low-temperature superplasticity of Ni–Co alloy by addition of nano-Si3Ni4 particles

In this paper, the low-temperature superplasticity of the electrodeposited Si3N4/Ni–Co nanocomposite was investigated for the first time at temperatures ranging from 673 to 823 K and at constant strain rates from 1 × 10−3 to 1 × 10−2 s−1. A maximum elongation of 692% was obtained at a temperature of 723 K and a strain rate of 5 × 10−3 s−1. High-strain rate superplasticity with an elongation of 371% was realized at a temperature of 723 K. It was found that the Si3N4 nanoparticles play an important role in the stability of the microstructure of the Si3N4/Ni–Co nanocomposite. The relatively large superplasticity of the nanocomposite compared to the Ni–Co alloy is discussed. Deformed microstructure, fracture and surface morphology are examined and the deformation mechanism of the composite is discussed.