Superplastic Properties of Al2O3/Ni-Mn Nanocomposite Fabricated by Electrodeposition

Ni-Mn nanocomposite reinforced by Al2O3 particles was fabricated by pulse electrodeposition. The average grain size is 60 nm and the content of Mn and Al2O3 particles is 0.3 and 0.6 wt pct, respectively. The superplastic deformation behavior was further studied at the temperatures ranging from 673 to 873 K. A maximum elongation of 530% is obtained in the tension test at a temperature of 773 K and at a strain rate of 1.67×10−3 s−1. The curves of the flow stress vs strain rate have features similar to the trend of conventional superplastic materials. The test temperature (773 K) equals to 0.35Tm, which means the material obtains low temperature superplasticity. The microstructures of the composite were examined and grain growth was observed during deformation.