On the grain growth behavior of Ni-W alloys in the extremely fine-grained regime

Abstract

Nanocrystalline pure FCC metals and some alloys are known to exhibit abnormal grain growth. Addition of solutes, such as W, has led to improved grain size stability in nanocrystalline Ni. While several groups have investigated grain growth behavior in Ni-based binary alloys, grain sizes greater than 15 nm were primarily investigated. In the present study, grain growth behavior is examined in grain size regime below 10 nm in nanocrystalline Ni-W alloys with 8 to 15 at% W at 773K. In this size regime, normal grain growth behavior was observed in these alloys, evidenced from (a) parabolic kinetics in plots of square of average grain size against annealing time, and (b) statistical self-similarity on the scaled size distribution in a log-normal plot.