The Law And Mechanism Of Filler/Aluminium Matrix Composites' Wettability Under Ultrasonic

Wetting is a common subject in both solidificated areas and welding scientific areas.So far,researches about Si Cp/Al wetting only focuses on reducing interfacial surface forces,or increasing the spreading area on the solid-liquid surface.at the same time,increasing the solubility of solid phases and liquid phases can make the area of interfacial dissolutive layer larger,lead to higher bonding strength.Wetting under ultrasonic is a good method to improve wettability between a melt drop and the substrate,which is also a clean way with no impurity involved.However,researches on ultrasonic wetting and the improvement of wettability are mainly focused on the spreading phenomenon,failing to reveal the intrinsical mechanism.According to the mechanism of dissolutive wetting,In order to coveredzinc-aluminum binary metal system,choosing 91Sn-9Zn and 95Zn-5Al alloys as the melt materials,1060 Aluminum alloys and high volume fraction Si Cp/Al composites,the latter has poor weldability.Through the contrast of contact angles and solid-liquid-gas triple line's variation,we draw the conclusion that how changing of ultrasonic time,holding temperature and alloying component effects the wetting and dissolution of the system.The dissolution of Zn-5Al alloy in pure Al is inforced when the time of assisting ultrasonic wave gets longer.Similarily,when raise the holding temperature from 420? to 460?,the wettability of Zn-5Al/Al and Zn-5Al/Si Cp-Al wetting systems both get worse,Observation of SEM images and contrast of EDS spectrum tells the reason that high temperature makes the cooling component apart from the eutectic composition,the flowability and dissolution in420? are better than in 460?.The rule of the dissolutive wetting approves correctly when the composition of metal system changes to Sn-9Zn alloy and 1060 Al,with two levels of temperature change to 260? and 300?.In order to analysis the spread of ultrasonic wave in the substrate board and the droplet above,use “acoustic module” in COMSOL Multiphysics software to make the simulation.When increasing the initial amplitude of the wave,the moving point in the Al vibrates stronger.The biggest amplitude appears in the centre position of the Al-MMCs board.The bonding strength relates straightly to the wetting behaviour of 95Zn-5Al alloys through high volume fraction Si Cp/Al.