In this paper

a new type of water-in-oil (W/O) emulsion suitable for coupling electrical pulse and ultrasonic treatment was developed

and the influence of water content on the viscosity and conductivity of the W/O emulsion was explored. It is found that when the water content is 40% and below

the W/O emulsion can maintain low electrical conductivity

have excellent dielectric properties

and better flow properties. Inconel 718 alloy was treated with water

W/O emulsion with mass fraction of 20% and 40%

and the surface morphology

wear resistance and corrosion resistance after treatment were investigated. The results showed that the surface of the sample treated with W/O emulsion with mass fraction of 40% is the smoothest

and has the best wear resistance and corrosion resistance. Compared with the substrate

the friction coefficient is reduced by 0.267

the wear loss is reduced by 43.2%

the corrosion current density is reduced by 86.9%

and the impedance is increased by 45.4%. The W/O emulsion can effectively fill the gap between the carbon brush and the sample

avoid the occurrence of discharge phenomenon. At the same time

the W/O emulsion can provide excellent lubrication effect

which can weaken the friction between ultrasonic vibration head and sample surface

and finally obtains better surface quality.