Recovery and Recrystallisation – a high-resolution EBSD study

Recovery and recrystallisation are fundamental processes that are crucial for making metals and alloys workable after deformation processes like rolling or drawing and allow a degree of control over a material's microstructure and mechanical properties. Recovery is described as rearrangement of lattice defects (dislocations) leading to annihilation and reduction of local stresses, while recrystallisation involves nucleation and growth of new defect and stress-free grains. The belief is that regions of high energy (elastic strain energy and defect density) are affected first. The distribution of the highest energy locations in a deformed microstructure should thus control the number and spacing of recrystallisation nuclei and hence final microstructure.

Although high angular resolution EBSD (HR-EBSD) has been extensively used to study local stress and dislocation density distributions in deformed metals there have (surprisingly) been no systematic studies on recrystallisation. This project will address this gap by applying HR-EBSD to a series of samples annealed at different temperatures and different times to induce recovery and static recrystallisation to different extents.