Creep in an electrodeposited nickel

This paper reports the experimental results on the creep behavior of electrodeposited ultrafine-grained nickel and its particle-reinforced nanocomposite. The objective of this research was to further improve the knowledge of the creep behavior of monolithic nickel and to explore the role of nano-sized SiO₂ particles in the potential creep strengthening of electrodeposited Ni nanocomposite. The creep behavior and microstructure of the pure ultrafine-grained nickel and its nanocomposite reinforced by 2 vol% nano-sized SiO₂ particles were studied at temperatures in the range from 293 to 573 K and at the applied tensile stresses between 100 and 800 MPa. The results indicate that the creep resistance of the nanocomposite may be noticeably improved compared to the monolithic nickel due to the interaction of the particles with dislocation motion. It was found that the applied stress interval can be divided into lower and higher stress intervals corresponding to dislocation (power-law) and exponential creep regions, respectively. Analysis of the creep data leads to the suggestion that the creep behavior of both electrodeposited nickel and its nanocomposite in power-law region may be grain boundary controlled. However, the mechanism responsible for the observed creep behavior at lower temperatures and the highest stresses is still not well established.