TEXTURES IN HCP TITANIUM AND ZIRCONIUM: INFLUENCE OF TWINNING

摘要

This paper is based on the comparison of the cold-rolling and subsequent annealing behavior of two hcp metals (cp-Ti and Zr702). A special attention is paid to the consequences of deformation twinning on texture and microstructure evolutions. The Ti sheet develops an important amount of twins in the first stages of deformation, whereas the Zr702 sheet deforms by slip only. Twinning is a very efficient grain fragmentation mechanism. It generates specific texture components at medium strains which smear out after 80% thickness reduction. Recrystallization mechanisms and kinetics are sensitive to the deformation substructure types and therefore to the occurrence of twinning. However the texture evolves quite few during recrystallization after 80% cold-rolling in both materials. Twinning orientation relationships are promoted in the misorientation distributions of the deformed microstructures but also slightly show up in the grain boundary populations of recrystallized materials.