Sulfur and superplasticity in electrodeposited ultrafine-grained Ni

The effect of sulfur (S) on superplasticity in ultrafine-grained electrodeposited nickel (Ni) was investigated by comparing the tensile behavior of Ni containing co-deposited S to electrodeposited Ni without S. Superplasticity was observed in Ni containing S in the temperature range of 350-490 °C, at an optimum constant strain rate of 10−3 s−1. Superplasticity was not achieved in Ni without S. The role of S on superplasticity was attributed to the combined effect of solute drag inhibited grain growth and the promotion of grain boundary sliding through weakened NiNi bonds across S enriched grain boundaries.