The recovery processes of cold deformed Ag and Ag-Ce alloy containing trace cerium were studied by XRD analysis.Based on Scherrer formula and an analytical program,the lattice distortion and subgrain size for both Ag ...The recovery processes of cold deformed Ag and Ag-Ce alloy containing trace cerium were studied by XRD analysis.Based on Scherrer formula and an analytical program,the lattice distortion and subgrain size for both Ag and Ag-Ce alloy were determined in the recovery process.The cold deformed high purity Ag showed tow recrystallization temperature,obvious lattice relaxation and age-softening.The trace Ce solute is an effective inhibitor for recovery softening of high purity Ag since it raises the recrystallization temperature and restrains the lattice relaxation.展开更多
Model of Casson nanofluid flow over a nonlinear shrinking surface is considered.Model of Tiwari and Das is applied to nanofluid comprising of sodium alginate with copper and silver.The governing nonlinear equations in...Model of Casson nanofluid flow over a nonlinear shrinking surface is considered.Model of Tiwari and Das is applied to nanofluid comprising of sodium alginate with copper and silver.The governing nonlinear equations incorporating the effects of the viscous dissipation are transformed into boundary value problems (BVPs) of ordinary differential equations (ODEs) by using appropriate similarity transformations.The resulting equations are converted into initial value problems (IVPs) using the shooting method which are then solved by Runge-Kutta method of fourth order.In order to determine the stability of the dual solutions obtained,stability analysis is performed and discovered that the first (second) solution is stable (unstable) and physically realizable (unrealizable).Both the thickness of the thermal boundary layer as well as temperature increase when the Casson parameter (β) is increased in the second solution.展开更多
Several important properties of the micron-powdered Sn-Ag-Cu-Ce solder, including the spreadability, spreading ratio, wetting time, and melting point, were investigated for verifying the effects of rare earth element ...Several important properties of the micron-powdered Sn-Ag-Cu-Ce solder, including the spreadability, spreading ratio, wetting time, and melting point, were investigated for verifying the effects of rare earth element Ce on solderabilities of micron-powdered Sn-Ag-Cu solder. The solidus and the liquidus of the micron-powdered Sn-Ag-Cu-Ce solder are 193.6℃ and 218.4℃, respectively, about 28℃ and 3℃ lower than the melting point of the block Sn-Ag-Cu solder, which reminds the existence of the surface effect of the micron-powdered solder. By adding Ce into Sn-Ag-Cu alloy, its wetting time on pure copper can be obviously decreased. For the Sn-Ag-Cu-0.03%Ce, the soldering temperature is 250℃, and the wetting time on pure copper is close to 1s, with the soldering temperature approaching to 260℃, the wetting time is dropped to 0.8s, which is close to the wetting time, 0.68s, of Sn-Pb solder at 235℃.展开更多
The isothermal section of the Ag-Cu-Ce ternary phase diagram at 500℃ containing 0～34 at% Ce have been determined by X-ray diffraction analysis and optical microscopy.It was found that Cu_2Ce-Ag_2Ce pseudo-binary sys...The isothermal section of the Ag-Cu-Ce ternary phase diagram at 500℃ containing 0～34 at% Ce have been determined by X-ray diffraction analysis and optical microscopy.It was found that Cu_2Ce-Ag_2Ce pseudo-binary system is characterized by having complete solid solubility at 500℃ and that the solid solubility of silver in Cu_5Ce is up to 41 at% at 500℃.The section consists of eight single phase re- gions,thirteen bi-phase regions and six tri-phase regions.展开更多
文摘The recovery processes of cold deformed Ag and Ag-Ce alloy containing trace cerium were studied by XRD analysis.Based on Scherrer formula and an analytical program,the lattice distortion and subgrain size for both Ag and Ag-Ce alloy were determined in the recovery process.The cold deformed high purity Ag showed tow recrystallization temperature,obvious lattice relaxation and age-softening.The trace Ce solute is an effective inhibitor for recovery softening of high purity Ag since it raises the recrystallization temperature and restrains the lattice relaxation.
基金Universiti Utara Malaysia (UUM) for the moral and financial support in conducting this research
文摘Model of Casson nanofluid flow over a nonlinear shrinking surface is considered.Model of Tiwari and Das is applied to nanofluid comprising of sodium alginate with copper and silver.The governing nonlinear equations incorporating the effects of the viscous dissipation are transformed into boundary value problems (BVPs) of ordinary differential equations (ODEs) by using appropriate similarity transformations.The resulting equations are converted into initial value problems (IVPs) using the shooting method which are then solved by Runge-Kutta method of fourth order.In order to determine the stability of the dual solutions obtained,stability analysis is performed and discovered that the first (second) solution is stable (unstable) and physically realizable (unrealizable).Both the thickness of the thermal boundary layer as well as temperature increase when the Casson parameter (β) is increased in the second solution.
文摘Several important properties of the micron-powdered Sn-Ag-Cu-Ce solder, including the spreadability, spreading ratio, wetting time, and melting point, were investigated for verifying the effects of rare earth element Ce on solderabilities of micron-powdered Sn-Ag-Cu solder. The solidus and the liquidus of the micron-powdered Sn-Ag-Cu-Ce solder are 193.6℃ and 218.4℃, respectively, about 28℃ and 3℃ lower than the melting point of the block Sn-Ag-Cu solder, which reminds the existence of the surface effect of the micron-powdered solder. By adding Ce into Sn-Ag-Cu alloy, its wetting time on pure copper can be obviously decreased. For the Sn-Ag-Cu-0.03%Ce, the soldering temperature is 250℃, and the wetting time on pure copper is close to 1s, with the soldering temperature approaching to 260℃, the wetting time is dropped to 0.8s, which is close to the wetting time, 0.68s, of Sn-Pb solder at 235℃.
基金The project supported by the National Natural Science Foundation of China
文摘The isothermal section of the Ag-Cu-Ce ternary phase diagram at 500℃ containing 0～34 at% Ce have been determined by X-ray diffraction analysis and optical microscopy.It was found that Cu_2Ce-Ag_2Ce pseudo-binary system is characterized by having complete solid solubility at 500℃ and that the solid solubility of silver in Cu_5Ce is up to 41 at% at 500℃.The section consists of eight single phase re- gions,thirteen bi-phase regions and six tri-phase regions.
