Ultrafast Precipitation Kinetics in an Ultrafine-Grained Al–Cu Alloy Used for Oil Drill Pipes

In the ultrafine-grained (UFG, 10 m) Al–Cu alloy. It was found the precipitation kinetics of θ phases in the UFG Al–Cu alloy occurred at several orders of magnitude faster than that can be predicted by conventional grain boundary precipitation theory. Considering ultrafast solute diffusion at the UFG length-scale, a developed/modified precipitation kinetics model at the UFG length-scale has been established. It yields predictions in satisfied accordance with experimental aging precipitation process/parameters of UFG Al–Cu alloys.