The structure and properties of microduplex Zr-Nb alloys

A fine grained microduplex structure can be obtained in Zr-2.5% Nb alloys by continuous recrystallisation in theα-β-region. These materials exhibit superplastic behaviour when deformed at temperatures above 620°C at low strain rates. The grain size is thermally stabilized by grain boundary precipitation, but increases rapidly during high temperature deformation. This enhancement can be explained by a model based on particle coalescence during grain neighbour switching.