The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalli...The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalline Cu-5%Cr can be further refined by cold drawing. After cold drawing, the grains of Cu-5%Cr alloy with grain size of 400-500 nm can be refined to be cellular structures and subgrains with size of 100-200 nm. Both strength and ductility of Cu-5%Cr alloy can be enhanced by cold drawing, and the optimal mechanical properties can be achieved with drawing deformation increasing. It is suggested that dislocation glide is still the main mechanism in plastic deformation of submicron crystalline Cu-5%Cr, but grain boundary slide and diffusion may play more and more important roles with drawing deformation increasing. When the cold drawn Cu-5%Cr wires are annealed at 550 ℃, fine recrystal grains with grain size of 200-300 nm can be obtained. Furthermore, there are lots of fine Cr particles precipitated during annealing, by which the recrystallization softening temperatures of the cold drawn Cu-5%Cr wires can be increased to 480-560 ℃. Due to the fact that Cr particles have the effect of restricting Cu grains growth, a favorable structural thermal stability of the submicron crystalline Cu-5%Cr can be achieved, and the submicron grained microstructure can be retained at high temperature annealing.展开更多
Cu-ZSM-5 type molecular sieves were synthesized hydrothermally in weak acid medium in the presence of F- ions. The structures of these samples were investigated.Increasing the amount of copper in synthesized samples t...Cu-ZSM-5 type molecular sieves were synthesized hydrothermally in weak acid medium in the presence of F- ions. The structures of these samples were investigated.Increasing the amount of copper in synthesized samples the unit cell volumes of Cu-ZSM-5 zeolites increase, while the adsorption peaks of Cu-ZSM-5 shift to lower wavenumbers.These facts and the results of the electron probe micrograph and XPS analyese indicate that copper was introduced into the framework of molecular sieve.展开更多
文摘The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalline Cu-5%Cr can be further refined by cold drawing. After cold drawing, the grains of Cu-5%Cr alloy with grain size of 400-500 nm can be refined to be cellular structures and subgrains with size of 100-200 nm. Both strength and ductility of Cu-5%Cr alloy can be enhanced by cold drawing, and the optimal mechanical properties can be achieved with drawing deformation increasing. It is suggested that dislocation glide is still the main mechanism in plastic deformation of submicron crystalline Cu-5%Cr, but grain boundary slide and diffusion may play more and more important roles with drawing deformation increasing. When the cold drawn Cu-5%Cr wires are annealed at 550 ℃, fine recrystal grains with grain size of 200-300 nm can be obtained. Furthermore, there are lots of fine Cr particles precipitated during annealing, by which the recrystallization softening temperatures of the cold drawn Cu-5%Cr wires can be increased to 480-560 ℃. Due to the fact that Cr particles have the effect of restricting Cu grains growth, a favorable structural thermal stability of the submicron crystalline Cu-5%Cr can be achieved, and the submicron grained microstructure can be retained at high temperature annealing.
文摘Cu-ZSM-5 type molecular sieves were synthesized hydrothermally in weak acid medium in the presence of F- ions. The structures of these samples were investigated.Increasing the amount of copper in synthesized samples the unit cell volumes of Cu-ZSM-5 zeolites increase, while the adsorption peaks of Cu-ZSM-5 shift to lower wavenumbers.These facts and the results of the electron probe micrograph and XPS analyese indicate that copper was introduced into the framework of molecular sieve.
