The recrystallization and texture evolution of cold-rolled FeCrAl-0.65 Nb and FeCrAl-1.2 Nb alloys thin-wall tubes annealed at 600−900℃ for 1−600 min were investigated.The microstructures were characterized by electr...The recrystallization and texture evolution of cold-rolled FeCrAl-0.65 Nb and FeCrAl-1.2 Nb alloys thin-wall tubes annealed at 600−900℃ for 1−600 min were investigated.The microstructures were characterized by electron back scattering diffraction,electron probe micro-analyzer and transmission electron microscopy.The Vickers hardness and room temperature tensile properties were tested.The results showed that the hardness of fully recrystallized FeCrAl-1.2 Nb alloy was higher and more likely to recrystallize than FeCrAl-0.65 Nb alloy.The weak texture strength of annealing sample was obtained and the proportion of<111>//ND texture increased.The fine Laves phase distributed uniformly in FeCrAl-0.65 Nb alloy had good pinning effect and inhibited recrystallization.Higher Nb content had little effects on tensile properties of thin-wall tube,and induced the formation of larger Laves phase.There was less fine Laves phase pinning in the large area adjacent to the blocky Laves phase,which resulted in easy recrystallization in FeCrAl-1.2 Nb alloy.展开更多
The effect of isochronal annealing on the deformation-induced defects in pure Cu and Cu-Ni-Si alloys is studied by positron annihilation spectroscopy.For the cold-rolled Cu,annealing up to 900℃ causes a gradual recov...The effect of isochronal annealing on the deformation-induced defects in pure Cu and Cu-Ni-Si alloys is studied by positron annihilation spectroscopy.For the cold-rolled Cu,annealing up to 900℃ causes a gradual recovery of the deformation-induced defects and monotonous decrease of the hardness.This indicates that its hardening is mainly related with defects such as dislocations.However,for the hot-rolled and quenched Cu-Ni-Si alloy,although there is a partial recovery of defects after annealing below 500℃,formation of additional defects is observed after annealing above 500℃.The hardness of Cu-Ni-Si alloy has a maximum value after annealing at 500℃,which suggests that the hardening of Cu-Ni-Si alloy is not due to defects,but primarily due to the precipitation formed during annealing.Further annealing of the Cu-Ni-Si alloy above 500℃ results in over-aging effect and the precipitates lose coherence with the host matrix,which leads to positron trapping by vacancy clusters in the incoherent interface region.展开更多
基金Project(2019YFB1901002)supported by the Key Project of Nuclear Safety and Advanced Nuclear Technology,ChinaProject supported by State Key Laboratory of Powder Metallurgy,China。
文摘The recrystallization and texture evolution of cold-rolled FeCrAl-0.65 Nb and FeCrAl-1.2 Nb alloys thin-wall tubes annealed at 600−900℃ for 1−600 min were investigated.The microstructures were characterized by electron back scattering diffraction,electron probe micro-analyzer and transmission electron microscopy.The Vickers hardness and room temperature tensile properties were tested.The results showed that the hardness of fully recrystallized FeCrAl-1.2 Nb alloy was higher and more likely to recrystallize than FeCrAl-0.65 Nb alloy.The weak texture strength of annealing sample was obtained and the proportion of<111>//ND texture increased.The fine Laves phase distributed uniformly in FeCrAl-0.65 Nb alloy had good pinning effect and inhibited recrystallization.Higher Nb content had little effects on tensile properties of thin-wall tube,and induced the formation of larger Laves phase.There was less fine Laves phase pinning in the large area adjacent to the blocky Laves phase,which resulted in easy recrystallization in FeCrAl-1.2 Nb alloy.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11075120,51071177the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China under Grant No J0830310.
文摘The effect of isochronal annealing on the deformation-induced defects in pure Cu and Cu-Ni-Si alloys is studied by positron annihilation spectroscopy.For the cold-rolled Cu,annealing up to 900℃ causes a gradual recovery of the deformation-induced defects and monotonous decrease of the hardness.This indicates that its hardening is mainly related with defects such as dislocations.However,for the hot-rolled and quenched Cu-Ni-Si alloy,although there is a partial recovery of defects after annealing below 500℃,formation of additional defects is observed after annealing above 500℃.The hardness of Cu-Ni-Si alloy has a maximum value after annealing at 500℃,which suggests that the hardening of Cu-Ni-Si alloy is not due to defects,but primarily due to the precipitation formed during annealing.Further annealing of the Cu-Ni-Si alloy above 500℃ results in over-aging effect and the precipitates lose coherence with the host matrix,which leads to positron trapping by vacancy clusters in the incoherent interface region.
