The effect of Cr content on the microstructural and textural evolution and the mechanical properties of Ni-Cr binary alloys

Abstract

The development of microstructure, texture and mechanical properties in single as well as two-phase recrystallized and aged Ni-Cr binary alloys are investigated. For this purpose, recrystallization studies were carried out on cold rolled binary alloys of Ni and Cr, containing 20%, 30%, 35% and 42% by weight of Cr from 550 °C to 900 °C. Recrystallization induced in the matrix γ-Ni phase was observed to be influenced by the deformation texture due to prior cold work and additionally by the concurrent precipitation of the α-Cr phase in the two-phase alloys. The recrystallization temperature of the alloys was determined by a net effect of the stored energy (dislocation density) and the mobility of the dislocations and the grain boundaries. The α-Cr precipitation resulted in the hardening of the aged two-phase alloys that was revealed by microhardness measurements as well as by miniature tensile experiments. The deformation texture after aging could be correlated to the expected change in stacking fault energy (SFE) due to Cr content. The recrystallization texture was influenced by the deformation texture as well as the α-Cr precipitation. The dominance of the P and the {2 3 6}< 3 ̅ 8 ̅ 5> type of recrystallization textures could be rationalized to the ‘oriented growth’ advantage offered by the concurrent α-Cr precipitation occurring more markedly on the grain boundaries of the other orientations. • Precipitation of α-Cr led to the hardening of the two-phase binary Ni-Cr alloys • The recrystallization temperature was non-monotonic with the Cr content • The deformation texture was determined by the Cr-content based change in the SFE • The α-Cr precipitation contributed to the recrystallization texture.