Here’s another:
“The microstructure and mechanical properties of ultrafine-grained ferritic alloys containing nanoclusters (NCs) are investigated. The NCs (diameter ∼3nm) as well as the grain size (∼200nm) remain stable at 1000°C. Substantial Hall–Petch strengthening occurs at room temperature. Surprisingly, the creep rate at 800°C is up to a factor of 10^8 slower than that predicted for diffusional creep. Possible reasons are the high NC coverage as well as Cr and W enrichment at the grain boundaries, and inhibition of self-diffusion.”
— http://tinyurl.com/2c7enbn
