Superplasticity of Ultra-Fine Grained Aluminium Alloys

摘要

Superplasticity requires a fine grain size, typically in the range of 1 - 10microns. Experiments have established that much finer grain sizes, in the near-nanometer range, may be achieved in Al-based alloys by using an intense plastic straining technique such as equal-channel angular (ECA) pressing. This report presents the microstructural characteristics and mechanical properties of several ultrafine-grained Al-based alloys processed by ECA pressing. The first demonstration of enhanced superplasticity at low temperatures and high strain rates revealed in commercial Al-alloys, having ultrafine-grained structure, are described.