Wetting Behavior And Interfacial Reaction Of Fe/Sn System Under Assistance Of Ultrasonic Vibration And Current

During the advanced preparation and process of materials,the liquid/solid interface was formed with the metal(or alloy)melting.By applying multi-physics field to this stage,a good manufacturing environment can be formed,in where the performance of products can be improved.Multi-physics field has recently become an indispensable technical support for preparation and process of advanced materials.But due to the basic research is poor in our country,which results in multi-physics field application on preparation and process of advanced materials is restricted seriously.Therefore,this article mainly studied the wetting behavior of pure Sn solder on pure Fe substrate under the action of the ultrasonic wave and the electric current,and analyzed the influence of different physical fields on the structure morphology and phase composition of solid-liquid interface during wetting.The main research conclusions were drawn,as following:(1)The wetting behavior and interfacial reaction mechanism of the solder droplets on the surface of the iron were studied with the ultrasonic effects.The results reveal that ultrasonic assist in the wetting force test of the Sn-Quartz system can increase the wetting force of the brazing filler metal to the base metal and in the wetting force test of the reaction system can accelerate the wetting time and increase the wetting force of the brazing filler metal to the base metal.With the increase of ultrasonic time and ultrasonic power wetting time of solder is reduced,the wetting force is increased and solid/liquid interface reaction is intensified,interface generated more and more thick more and more dense intermetallic compound,the base metal surface relative to the original surface become rough,thus easier to wetting process,so that the wetting force is increased.(2)The wetting behavior and mechanism of the solder droplets on the surface of the iron were studied under the action of direct current.The results show that the time of solder wetting on iron can be cut down and the wetting force can be increased with the action of direct current.Due to the action of electric current,a magnetic pressure gradient force is generated in the molten solder,which causes the solder to climb up along the interface,so that the wetting force is increased.In addition,due to the generation of thermal gradient and component gradient in the molten solder,convection occurs,resulting in the diffusion of atoms at the interface layer,so that the interface reaction intensifies and the interface product layer thickens.(3)The study also found that under the coupled action of electric current and ultrasonic vibration wetting spreading process is unbalanced,ultrasonic vibration and current instantaneous high-energy join broke the wetting balance system of the original,the molten solder in additional force and electromagnetic compression force under the action of ultrasonic spreading wetting(climb),the wet process of driving force for the average due to ultrasonic transmission ultrasonic additional pressure gradient and current load average magnetic pressure gradient.At the same time,the improvement of wetting behavior under the coupling effect of ultrasonic vibration and current is the result of ultrasonic cavitation effect,acoustic flow effect,current thermal effect,electromagnetic effect and electromigration effect.Based on the above research,in the wet process of metal system,the effect of multi-physics field can significantly improve its wettability,promoted interfacial atomic diffusion,and solid/liquid interface reaction is intensified.the results of this study are expected to enrich the relevant basic theory of wettability during soleringor brazing,and to provide the scientific basis for improving and upgrading the processing techniques of manufacturing and processing of advanced materials.