The corrosion behavior of electrodeposited Ni with normal and bimodal grain size distribution was investigated.The microstructure of samples was researched by SEM,EBSD,TEM and XRD.The corrosion behavior was studied by...The corrosion behavior of electrodeposited Ni with normal and bimodal grain size distribution was investigated.The microstructure of samples was researched by SEM,EBSD,TEM and XRD.The corrosion behavior was studied by potentiodynamic tests and electrochemical impedance.Nanocrystalline Ni with(100)and(111)textures was prepared by an electrodeposition method.The Ni samples with different grain size distributions and twins were then obtained by heat treatment of nanocrystalline Ni at different temperatures.The effect of grain size on corrosion behavior of the sample depends on the ability of the environment to passivate.In the case where passive film forms on the sample surface,the corrosion resistance of the sample increases with decreasing grain size.Conversely,the corrosion resistance decreases with decreasing grain size when there is no passivation.The corrosion behavior of samples with bimodal grain size distribution obeys the rule of mixture.展开更多
A Thermecmastor-Z hot deformation simulator,optical microscopy,XRD and TEM were employed to characterize the flow stress behavior and microstructure of twin roll cast ZK60 magnesium alloy during initial stage of hot c...A Thermecmastor-Z hot deformation simulator,optical microscopy,XRD and TEM were employed to characterize the flow stress behavior and microstructure of twin roll cast ZK60 magnesium alloy during initial stage of hot compression at elevated temperature of 300 ℃ and 400 ℃ and a given strain rate of 10-2s-1.The results suggest that flow stress drop during initial stage of hot compression at 300℃,generally led by dynamic recrystallization,is attributed to twinning,correspondingly to dynamic recrystallization as deformation temperature is raised to 400 ℃.展开更多
基金Projects(51571211,51731010,51471028) supported by the National Natural Science Foundation of ChinaProject(DP160105066) supported by Australian Research Council
文摘The corrosion behavior of electrodeposited Ni with normal and bimodal grain size distribution was investigated.The microstructure of samples was researched by SEM,EBSD,TEM and XRD.The corrosion behavior was studied by potentiodynamic tests and electrochemical impedance.Nanocrystalline Ni with(100)and(111)textures was prepared by an electrodeposition method.The Ni samples with different grain size distributions and twins were then obtained by heat treatment of nanocrystalline Ni at different temperatures.The effect of grain size on corrosion behavior of the sample depends on the ability of the environment to passivate.In the case where passive film forms on the sample surface,the corrosion resistance of the sample increases with decreasing grain size.Conversely,the corrosion resistance decreases with decreasing grain size when there is no passivation.The corrosion behavior of samples with bimodal grain size distribution obeys the rule of mixture.
基金Project(10020072) supported by Brain Pool Program of Korea Government and Core Technology R & D Program for the Development of High Performance Eco-friendly Structural Materials of the Korean Ministry of Commerce, Industry and Energy
文摘A Thermecmastor-Z hot deformation simulator,optical microscopy,XRD and TEM were employed to characterize the flow stress behavior and microstructure of twin roll cast ZK60 magnesium alloy during initial stage of hot compression at elevated temperature of 300 ℃ and 400 ℃ and a given strain rate of 10-2s-1.The results suggest that flow stress drop during initial stage of hot compression at 300℃,generally led by dynamic recrystallization,is attributed to twinning,correspondingly to dynamic recrystallization as deformation temperature is raised to 400 ℃.
