The wetting behavior of molten Zr55Cu30Al10Ni5 on Al2O3 was studied by the sessile drop method in high vacuum. The results show that wetting kinetic at 1 163 K is composed of three stages: incubation, quasi-steady dec...The wetting behavior of molten Zr55Cu30Al10Ni5 on Al2O3 was studied by the sessile drop method in high vacuum. The results show that wetting kinetic at 1 163 K is composed of three stages: incubation, quasi-steady decrease and trend constant. Precursor film forms surrounding the wetting tip when wetting temperature is above 1 163 K. Formation of precursor film is related to the change of triple line configuration and results in good wettability. Chemical reaction dos not occur at the wetting interface. Al2O3 is an excellent reinforcement for Zr55Cu30Al10Ni5 matrix composite in terms of wettability and reactivity. The kinetic relationship of spreading ratio with spreading time was also investigated.展开更多
The effect of direct electric current on the wetting behavior of molten Bi on Cu substrate at 370℃ was investigated by the sessile drop method. The wettability of molten Bi on Cu without an applied current is poor an...The effect of direct electric current on the wetting behavior of molten Bi on Cu substrate at 370℃ was investigated by the sessile drop method. The wettability of molten Bi on Cu without an applied current is poor and the spreading time required to form the steady-state contact angle （about 102°） is approximately 30 min. With the increase of the applied electric current, the spreading of molten Bi on Cu is accelerated significantly and the steady-state contact angle decreases considerably. The cross-section SEM micrographs of the solidified Bi droplet on Cu substrate show that the electric current has a marked effect on the convection of melt. Correspondingly, the application of an electric current obviously enhances the dissolution of Cu into Bi melt, which may change the wetting triple line configuration. The improvement of wettability induced by electric current is also related to the additional driving force for wetting provided by the electromagnetic pressure gradient force.展开更多
基金Project(G2000067201) supported by the National Basic Research Program of China
文摘The wetting behavior of molten Zr55Cu30Al10Ni5 on Al2O3 was studied by the sessile drop method in high vacuum. The results show that wetting kinetic at 1 163 K is composed of three stages: incubation, quasi-steady decrease and trend constant. Precursor film forms surrounding the wetting tip when wetting temperature is above 1 163 K. Formation of precursor film is related to the change of triple line configuration and results in good wettability. Chemical reaction dos not occur at the wetting interface. Al2O3 is an excellent reinforcement for Zr55Cu30Al10Ni5 matrix composite in terms of wettability and reactivity. The kinetic relationship of spreading ratio with spreading time was also investigated.
基金Project(50704001) supported by the National Natural Science Foundation of China
文摘The effect of direct electric current on the wetting behavior of molten Bi on Cu substrate at 370℃ was investigated by the sessile drop method. The wettability of molten Bi on Cu without an applied current is poor and the spreading time required to form the steady-state contact angle （about 102°） is approximately 30 min. With the increase of the applied electric current, the spreading of molten Bi on Cu is accelerated significantly and the steady-state contact angle decreases considerably. The cross-section SEM micrographs of the solidified Bi droplet on Cu substrate show that the electric current has a marked effect on the convection of melt. Correspondingly, the application of an electric current obviously enhances the dissolution of Cu into Bi melt, which may change the wetting triple line configuration. The improvement of wettability induced by electric current is also related to the additional driving force for wetting provided by the electromagnetic pressure gradient force.
